下图是高等动物细胞亚显微结构模式图，请据图回答。([ ]中填序号，横线上填文字) 图中[③]（）与动物细胞的有丝分裂有关。

下图表示种群年龄组成的三种类型，其中属于稳定型的是（）

A:乙和丙 B:甲和乙 C:甲 D:乙

患者男，50岁，牙列缺失，患者力较大，全口义齿修复一个月后基托折裂，重新修复的话最好做何种改进（）

A:采用种植修复 B:增加基托厚度 C:改用金属基托 D:扩大基托范围 E:采用硅橡胶印模

化学结构为的药物临床用作（　）.

A:抗血吸虫病药 B:抗菌药 C:驱肠虫药 D:抗疟药 E:抗丝虫病药

图中的药材的特征习称（）

A:狮子盘头 B:钉头 C:连珠斑 D:怀中抱月 E:虎皮斑

曲线与平面x+z=a的交线在yoz平面上的投影方程是（）。

A:A B:B C:C D:D

Directions: Study the following picture carefully and write an essay entitled "Noise Pollution. " In the essay you should (1) show your understanding about the issue, (2) state your opinions and use facts to support your statement.

Noise can be harmful to people. As the population grows, we experience an increasing use of all kinds of machines, such as automobiles, televisions and stereos. These things and many others that seem to benefit people a lot may turn out to be a source of noise pollution. Nowadays noise pollution is getting so serious that people all over the world are paying greater attention to it and seeking ways to deal with the problem.
Noise does harm to people physically. Studies have proved that long exposure to noise intensity will lead to the loss of hearing. It also does great harm to people who suffer from heart trouble. So there is a widespread concern over the noise pollution. Moreover, noise also disturbs people’s mind. Some of the work sites make a lot of noise at night, leaving people in a sleepless state. Noise from a stereo and television or things like that can be annoying. It may drive people "mad" and give rise to quarrels among neighbors.
Now more people realize that silence is a natural resource and must be protected by law. Research findings show that while we all find company in sound, in the meanwhile we all need a little silence from time to time.

[70783c8e4b842ba561899a272e9ed591.gif]

这个标志是何含义？（）

A:人行横道 B:注意行人 C:注意儿童 D:学校区域

2987（）

A:A B:B C:C D:D