下列现象中属于渗透作用的是（） A．水分子通过细胞壁 B．葡萄糖分子通过半透膜 C．

淡水资源的缺乏已成为制约社会发展的重要因素，从浩瀚的海洋里获取淡水，对解决淡水危机具有重要意义。某小组针对这一现状，提出问题并在实验室进行了以下探究。

【提出问题】（1）________________________________________________

【实验用品】酒精灯、试管、单孔橡皮塞、玻璃导管、铁架台、烧杯、胶头滴管、海水、硝酸银溶液。

【实验过程】如下图组装仪器并检查装置气密性。

（2）向大试管加入5～10mL海水，塞好橡皮塞，用酒精灯加热。加热一段时间后，小试管内收集到很少液体，试管口有大量白雾。该小组同学建议对该装置进行改进，你认为改进的措施为：________________________。

（3）向小试管里的冷凝水中滴加几滴硝酸银溶液，现象为：________________________。

【得出结论】通过上述实验探究，你得出的结论是：____________________________________。

【反思交流】①对海水淡化后剩余资源，请提出一种合理利用的措施：________________________。

②“蒸馏法淡化海水”的思路是想办法将水从混合物中分离出来。请列举一种与上述原理相同的混合物分离的例子：________________________________________________。

关于心胸比率，下列哪项描述正确（）

A.心脏最大横径与胸廓最大横径的比率

B.心脏最大横径是左心室最大横径

C.胸廓最大横径为最大胸廓处的外径

D.充分呼气后这一比率为1：2

E.未成年人可能较小

患者，女性，28岁，妊娠5个月。主诉近3个月来刷牙出血严重。

如果诊断为妊娠期龈炎，这种疾病的发生与下列哪一因素最密切相关（）

A.年龄

B.体重

C.全身健康状况

D.口腔卫生状况

E.妊娠时间长短

A real estate developer in Florida, desiring to protect his high-rise apartment building on the beach from hurricane damage, has planted sea oats in two rows in front of his building in order to encourage the development of sand dunes between the water and his building.
Which of the following, if true, casts the most doubt on the probable effectiveness of the developer’s plan ？（）

A. Sand dunes provide little protection for tall buildings against the wind, which is sufficiently powerful even in minor hurricanes to cause serious damage to buildings.

B. Sand dunes have been shown to provide effective protection against the storm surge, the pounding waves driven by hurricane-force winds onto dry land.

C. Although sea oats will lead to the growth of sand dunes over many years, it would be far faster to build concrete bunkers between the building and the water.

D. Hurricane insurance has become so expensive that many owners of beachfront property choose not to buy it.

E. The developer has invested in reinforced steel girders and shatterproof glass as a way of minimizing damage to his building in the event that a hurricane hits the area.

实行计划生育丈夫有没有责任？（）

A.有；

B.没有；

C.不确定。