生物学能有今天的辉煌成就,离不开众多科学家倾其一生孜孜不倦的研究。下面提及的著名的科学家的实验中精心设置了对照实验的是（      ）①达尔文提出以自然选择学说为中心的生物进化理论②孟德尔通过豌豆杂交实验发现基因的分离定律和基因的自由组合定律③赫尔希和蔡斯证明在噬菌体中DNA是遗传物质，而蛋白质不是遗传物质 <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-border-alt: solid windowtext .5pt; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext; mso-table-lspace: 9.0pt; mso-table-rspace: 9.0pt; mso-table-anchor-vertical: paragraph; mso-table-anchor-horizontal: page; mso-table-left: 441.9pt; mso-table-top: 13.1pt" border="1" cellspacing="0" cellpadding="0" align="left" _dj="MsoNormalTable"><tbody><tr style="HEIGHT: 14.5pt; 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: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; BORDER-TOP: windowtext 1pt solid; BORDER-RIGHT: windowtext 1pt solid; PADDING-TOP: 0cm; mso-border-alt: solid windowtext .5pt" width="43">类别</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; 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="36">Ⅰ</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; 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="28">Ⅱ</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; 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="36">Ⅲ</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14.5pt; 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="33">Ⅳ</td></tr><tr style="HEIGHT: 14pt; mso-yfti-irow: 1"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; 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="43">父亲</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; 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="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; 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="28">-</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; 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="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 14pt; 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="33">-</td></tr><tr style="HEIGHT: 6pt; mso-yfti-irow: 2"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; 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="43">母亲</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; 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="36">-</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; 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="28">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; 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="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 6pt; 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="33">-</td></tr><tr style="HEIGHT: 13.5pt; mso-yfti-irow: 3"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; 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="43">儿子</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; 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="36">+ -</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; 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="28">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; 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="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.5pt; 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="33">+ -</td></tr><tr style="HEIGHT: 13.25pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes"><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: windowtext 1pt solid; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 32.4pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; 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="43">女儿</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; 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="36">+ -</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 21.3pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; 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="28">-</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 27pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; 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="36">+</td><td style="BORDER-BOTTOM: windowtext 1pt solid; BORDER-LEFT: medium none; PADDING-BOTTOM: 0cm; PADDING-LEFT: 5.4pt; WIDTH: 25pt; PADDING-RIGHT: 5.4pt; HEIGHT: 13.25pt; 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="33">-</td></tr></tbody></table>  ④艾弗里证明促使R型细菌转化成S型细菌的物质是DNA