肺炎链球菌主要的致病物质是A、荚膜B、菌毛C、自溶酶D、内毒素E、外毒素

孕妇最常见的营养缺乏病是

A、蛋白质-能量营养不良

B、营养性贫血

C、脚气病

D、干眼病

E、骨质软化病

请帮忙给出正确答案和分析，谢谢！

What is the speaker doing？

A．Explaining the campus architecture to visitors.

B．Providing orientation for new campus employees.

C．Familiarizing new students with the campus.

D．Advising students about which classes to take.

请帮忙给出正确答案和分析，谢谢！

What can we infer from the passage？

A．We are amused by our own acts of absent-mindedness.

B．We are tired of stories about absent-minded professors.

C．Memory "tricks" are nothing dangerous.

D．We can"t hear enough stories about forgetful professors.

请帮忙给出正确答案和分析，谢谢！

胰岛δ细胞分泌的生长抑素是

A.神经递质

B.旁分泌的激素

C.自分泌的激素

D.细胞因子

E.谷胱甘肽

请帮忙给出正确答案和分析，谢谢！

吸味浓度是指吸烟时感受到的烟气的浓淡程度，它与()。

A.烟叶内各组分物质之间协调、平衡程度有关

B.烟叶内各组分物质之间协调、平衡程度无关

C.烟叶内各组分物质之间协调程度无关

D.烟叶内各组分物质之间平衡程度无关

请帮忙给出正确答案和分析，谢谢！