已知血友病是由性连锁的单基因所决定的，假如某个家庭中父亲和母

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问题单项选择题

已知血友病是由性连锁的单基因所决定的，假如某个家庭中父亲和母亲均正常，但是有一个血友病的儿子，那么他们将会有一个血友病女儿的概率是( )

A．1/4
B．1/2
C．1/8
D．0

答案

参考答案：D

解析：由于父亲正常，所以其基因型为X^AY，提供给女儿的基因为X^A，所以女儿不可能患病。所以选择D。

阅读理解

根据短文内容，判断正（T）误（F）。

Hello! My name is Mike. I am from the USA. Now I'm in China with my parents. I like China. I like

Chinese food, too. I have breakfast at home. I eat eggs, bread and porridge. I don't like milk. I have no time

to go home for lunch. So I have it at school. The lunch in our school is good. I can have different kinds of

food for lunch. I eat rice, meat and vegetables. Sometimes I have noodles and dumplings. I have supper at

home with my parents. We have fish, meat, vegetables and fruit. Sometimes we go out to eat with our

friends.

( )1. Mike is in China with his parents.

( )2. He eats eggs, bread and salad for breakfast.

( )3. He has lunch at home.

( )4. He has noodles and dumplings for dinner.

( )5. Sometimes they go out to eat.

单项选择题 A1/A2型题

符合 * * 解剖特点的是（）

A. * * 上窄下宽

B. * * 表面由单层柱状上皮覆盖

C. * * 环绕宫颈部分称为穹隆

D.前穹隆顶端为腹腔最低处

E.开口于 * * 前庭前部