在煮过的和没煮过的马铃薯片上分别滴几滴过氧化氢。在马铃薯片X上出现泡沫，在马铃薯片Y上没有泡沫，以下哪一项是正确的解释？（    ）

试卷相关题目

• 1目前，治疗肿瘤所采用的“化疗”，是使用化学药物抑制人体肿瘤细胞的DNA复制，使这些肿瘤细胞停留在（    ）

  A.分裂前期

  B.分裂后期

  C.分裂中期

  D.分裂间期

  开始考试点击查看答案
• 2研究人员对取自4种不同生物的部分生活细胞进行分析、观察等实验，获得的结果如下表（表中“∨”表示有，“×”表示无），试判断A、B、C、D4种细胞中最可能取自下列哪组生物？（    ） <table border="1" cellspacing="0" cellpadding="0" _dj="MsoNormalTable"><tbody><tr><td width="35"> </td><td width="62">核膜</td><td width="62">叶绿素</td><td width="62">叶绿体</td><td width="62">线粒体</td><td width="62">中心体</td><td width="62">核糖体</td><td width="132">纤维素酶处理的结果</td></tr><tr><td width="35">A</td><td width="62">×</td><td width="62">∨</td><td width="62">×</td><td width="62">×</td><td width="62">×</td><td width="62">∨</td><td width="132">无变化</td></tr><tr><td width="35">B</td><td width="62">×</td><td width="62">×</td><td width="62">×</td><td width="62">×</td><td width="62">×</td><td width="62">∨</td><td width="132">无变化</td></tr><tr><td width="35">C</td><td width="62">∨</td><td width="62">×</td><td width="62">×</td><td width="62">∨</td><td width="62">×</td><td width="62">∨</td><td width="132">外层结构被破坏</td></tr><tr><td width="35">D</td><td width="62">∨</td><td width="62">∨</td><td width="62">∨</td><td width="62">∨</td><td width="62">∨</td><td width="62">∨</td><td width="132">外层结构被破坏</td></tr></tbody></table>

  A.乳酸菌、团藻、水稻、光合细菌

  B.水稻、光合细菌、乳酸菌、团藻

  C.光合细菌、乳酸菌、水稻、团藻

  D.团藻、水稻、乳酸菌、光合细菌

  开始考试点击查看答案
• 3有人做过这样的实验：把变形虫的核从其体内取出，观察无核变形虫中的一系列变化的特点，推测出a～d四个现象，并提出相应的推测理由①②③④，请选出推测现象和理由均正确的一个组合（    ）推测现象：a．失去核的变形虫，虽然停止伸出伪足，但在几天后核就再生，能正常活动b．失去核的变形虫，细胞质功能逐渐衰退，几天内将死亡c．失去核的变形虫，虽然反复进行数次无丝分裂，但结果还是死亡d．除去核以后，细胞质活动反而暂时提高，因此细胞分裂变得更加旺盛推测理由：①许多生物器官都有再生能力，核也能再生②只有细胞核内才是控制细胞质代谢和遗传的中心③在没有核的细胞质里，也残存着分裂的能力④核能抑制细胞的过度分裂

  A.a～①

  B.b～②

  C.c～③

  D.d～④

  开始考试点击查看答案
• 4下列过程中，涉及肽键数量变化的是（    ）

  A.洋葱根尖细胞染色体的复制

  B.用纤维素酶处理植物细胞

  C.小肠上皮细胞吸收氨基酸

  D.蛋清中加入NaCl使蛋白质析出

  开始考试点击查看答案
• 5从一动物细胞中得到两类大分子有机物X,Y,已知细胞中X的含量大于Y,用胃液处理,X被分解而Y不变.X含有化学元素N,有的还含有S,Y含有化学元素N和P,它们与碘都没有颜色反应,且细胞膜上有X而无Y.下列有关X,Y的叙述,错误的是（    ）

  A.X可能是蛋白质

  B.Y的基本组成单位可能是核苷酸

  C.细胞膜上的X可能是载体

  D.Y只存在于细胞核中

  开始考试点击查看答案
• 6表是某同学关于酶特性研究的实验操作步骤，该实验的假设是（    ）项  目    试管甲    乙1    注入可溶性淀粉溶液    2mL    －2    注入蔗糖溶液    －    2mL3    注入新鲜的蔗糖酶溶液    2mL    2mL4    适宜温度下保温5min5    注入斐林试剂    2mL    2mL6    酒精灯隔水加热1 min7    观察现象

  A.酶具有专一性

  B.酶具有催化功能

  C.酶具有高效性

  D.温度会影响酶的活性

  开始考试点击查看答案
• 7已知在离体的番茄根吸收K+与氧分压的关系实验中，当氧分压为5％～10％时，K+吸收量达到最高值。之后氧分压继续提高，一直到100％，K+的吸收量不再增加，对此，合理的解释是（    ）

  A.氧分压高抑制主动运输

  B.氧分压高影响载体活动

  C.外界溶液中K+减少

  D.载体不会增加

  开始考试点击查看答案
• 8下列关于哺乳动物体内三大营养物质代谢的叙述，不正确的是（    ）

  A.用¹⁵N标记的苯丙氨酸饲喂小鼠后，在其体内检测不到¹⁵N标记的酪氨酸

  B.当体内脂肪的分解速度加快时，意味着糖类的供应不足

  C.肝细胞中内质网的功能出现障碍，脂蛋白的合成受阻

  D.肝糖元和肌糖元去路的差异，与所在细胞功能密切相关

  开始考试点击查看答案
• 9下表表示某种食物中的4种氨基酸的含量和人体蛋白质中这4种氨基酸的平均含量。试问：如果人食用这种食物，在人体中发生下列哪种生理过程，才能使食物中的这4种氨基酸得到充分合理的利用（    ） <table style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; BORDER-COLLAPSE: collapse; MARGIN-LEFT: 6.75pt; BORDER-TOP: medium none; MARGIN-RIGHT: 6.75pt; BORDER-RIGHT: medium none; mso-table-layout-alt: fixed; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-table-lspace: 9.0pt; mso-table-rspace: 9.0pt; mso-table-anchor-vertical: paragraph; mso-table-anchor-horizontal: page; mso-table-left: 102.0pt; mso-table-top: 2.95pt" border="1" cellspacing="0" cellpadding="0" align="left" _dj="MsoNormalTable"><tbody><tr style="HEIGHT: 15.35pt; mso-yfti-irow: 0; mso-yfti-firstrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 109.15pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt" width="146">氨基酸</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 62.25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="83">丝氨酸</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="87">组氨酸</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="87">酪氨酸</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" width="87">甘氨酸</td></tr><tr style="HEIGHT: 14.65pt; mso-yfti-irow: 1"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 109.15pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.65pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="146">食物中</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 62.25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.65pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="83">0.01g/g</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.65pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="87">0.10 g/g</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.65pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="87">0.05 g/g</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.65pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="87">0.20 g/g</td></tr><tr style="HEIGHT: 15.35pt; mso-yfti-irow: 2; mso-yfti-lastrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 109.15pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="146">人体蛋白质中</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 62.25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="83">0.1 g/g</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="87">0.23 g/g</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="87">0.13 g/g</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 65.5pt; PADDING-RIGHT: 5.4pt; HEIGHT: 15.35pt; BORDER-TOP: medium none; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" width="87">0.04 g/g</td></tr></tbody></table>

  A.呼吸作用

  B.转氨基作用

  C.脱氨基作用

  D.氧化作用

  开始考试点击查看答案
• 10容积相同的几只玻璃缸，同龄且发育状态相同的小蝌蚪60只，蝌蚪常用饲料，未经处理的具有生物活性的甲状腺激素，50℃温水处理10分钟的原来具有生物活性的甲状腺激素等。用上述试剂、材料和用具设计实验探究甲状腺激素处理后的生物活性变化。实验方案见下表（√代表等量适量加入）  <table style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; mso-table-layout-alt: fixed; mso-border-alt: solid windowtext .75pt; mso-padding-alt: 0cm 0cm 0cm 0cm; mso-border-insideh: .75pt solid windowtext; mso-border-insidev: .75pt solid windowtext; mso-cellspacing: 0cm" border="1" cellspacing="0" cellpadding="0" _dj="MsoNormalTable"><tbody><tr style="HEIGHT: 22pt; mso-yfti-irow: 0; mso-yfti-firstrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 22pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">玻璃缸编号</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 45pt; PADDING-RIGHT: 0cm; HEIGHT: 22pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="60">蝌蚪数</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 22pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">常用饲料</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 72pt; PADDING-RIGHT: 0cm; HEIGHT: 22pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="96">甲状腺激素</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 126pt; PADDING-RIGHT: 0cm; HEIGHT: 22pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="168">50℃处理10min的甲状腺激素</td></tr><tr style="HEIGHT: 21pt; mso-yfti-irow: 1"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 21pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">甲</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 45pt; PADDING-RIGHT: 0cm; HEIGHT: 21pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="60">20</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 21pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">√</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 72pt; PADDING-RIGHT: 0cm; HEIGHT: 21pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="96"> </td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 126pt; PADDING-RIGHT: 0cm; HEIGHT: 21pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="168"> </td></tr><tr style="HEIGHT: 14.2pt; mso-yfti-irow: 2"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 14.2pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">乙</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 45pt; PADDING-RIGHT: 0cm; HEIGHT: 14.2pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="60">20</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 14.2pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">√</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 72pt; PADDING-RIGHT: 0cm; HEIGHT: 14.2pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="96">√</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 126pt; PADDING-RIGHT: 0cm; HEIGHT: 14.2pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="168"> </td></tr><tr style="HEIGHT: 7.1pt; mso-yfti-irow: 3; mso-yfti-lastrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 7.1pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">丙</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 45pt; PADDING-RIGHT: 0cm; HEIGHT: 7.1pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="60">20</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 63pt; PADDING-RIGHT: 0cm; HEIGHT: 7.1pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="84">√</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 72pt; PADDING-RIGHT: 0cm; HEIGHT: 7.1pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="96"> </td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 0cm; WIDTH: 126pt; PADDING-RIGHT: 0cm; HEIGHT: 7.1pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .75pt" width="168">√</td></tr></tbody></table>观察蝌蚪完成发育所需的天数，下列预期及分析得出的结论中，正确的有（    ）

  A.现象：若发育所需的天数乙大于丙， 结论：甲状腺激素处理后活性降低

  B.现象：若发育所需的天数甲同于丙， 结论：甲状腺激素处理后活性不变

  C.现象：若发育所需的天数甲>丙>乙， 结论：甲状腺激素能促进生长发育

  D.现象：若发育所需的天数甲>乙>丙， 结论：甲状腺激素处理后活性升高

  开始考试点击查看答案