9.Why doesn’t the woman go to live with her son and her daughter-in-law?
A.Because her son’s apartment is very small.
B.Because her son doesn’t want her to live with them.
C.Because she doesn’t want to leave her old apartment.
Conversation 5
8.What does the woman want the doctor to do?
A.To give her some good suggestions.
B.To give her an examination.
C.To operate on her.
7.What’s wrong with the woman?
A.She has a headache.
B.There is something wrong with her stomach.
C.She feels bored and doesn’t want to do anything.
6.What’s Jenny’s new telephone number?
A.6880015. B.6882315. C.6883215.
Conversation 4
5.Where are the two speakers going?
A.To a birthday party. B.To a department store. C.To Lily’s school.
4.What does the woman want the man to do?
A.To go to Alice’s birthday party with her.
B.To tell her when Alice’s birthday is.
C.To buy her a birthday present.
Conversation 3
3.When is the woman’s birthday?
A.Tomorrow.
B.The day after tomorrow.
C.In two weeks.
2.What can we learn from the conversation?
A.The man’s brother speaks very good Chinese.
B.The man wants to learn some Chinese.
C.The woman is learning Chinese.
Conversation 2
1.What is in the man’s hand?
A.An old English-Chinese dictionary.
B.A new English-Chinese dictionary. .
C.A new Chinese-English dictionary.
34.(10分)环境激素是指由于人类的生产和生活活动而排放到周围环境中的某些化学物质。为研究环境激素H对小鼠产生精子数的影响,用玉米油和环境激素H分别处理对照组和实验组雄性小鼠(每千克体重注射12.5mL,每天1次,连续21天,n=20)。实验结束后,对每只小鼠产生的精子计数。实验内容及结果见下表。
|
对照组 |
实验组 |
|
1 |
2 |
||
注射物 |
玉米油 |
H(浓度100mg/L) |
H(浓度200mg/L) |
精子数均值(×107个) |
7.13 |
5.09 |
4.35 |
请分析并回答:
(1)表中数据显示,环境激素H浓度增高,小鼠生成精子数___________。
(2)小鼠脑中的____________调节______________释放的相关激素能刺激睾丸分泌雄激素和少量雌激素,并生成精子。精子是由睾丸中_______________细胞(2n)经_________________发育来的。
(3)正常雄鼠体内性激素浓度偏高会抑制脑中相关激素的释放,该调节方式称为________________。
(4)有的环境激素可造成精子染色体缺失,这是精子DNA分子发生________和DNA片段________所致。
(5)环境激素可沿着________传递进入人体,被靶__________接受后干扰精子生成,从而使人的生育能力降低。
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