问题 单项选择题 A1/A2型题

生物芯片上对待测样品进行分离采用的方法是()。

A.超速离心

B.薄层层析

C.活性炭吸附

D.介电电泳

E.离子交换

答案

参考答案:D

解析:待测样品大多是成分复杂的混合体,通常要经过分离和标记,经典的生物化学分离对分离细胞蛋白质等含量甚微的靶分子比较困难,因而研制者在芯片上制作微型样品处理系统,如介电电泳,大大提高了分离的效率。

阅读理解

阅读理解。

      Should teenagers help their parents do chores? If you want to be an independent(独立的)one, or

you don't want your parents to be too tired, do chores at home.

     I have a classmate called Li Ting. She is the only child in her family. Her parents love her so much

that they don't let her do any chores.  On weekdays she gets up, has meals, goes to school, has lessons,

comes back home, does homework and goes to bed. While on weekends, she only plays with her friends. So she doesn't know how to do chores.  One day, her father was ill in hospital.  Her mother had to take

care of her father in the hospital and couldn't cook meals for her for a week.  Li Ting didn't know how to

cook meals.  She had a lot of trouble cooking meals and often felt hungry.  She only had instant noodles

for her meals.

1. How many children are there in Li Ting's family?

A. Two.    

B. Three    

C. One.    

D. Four.

2. The writer thinks it is______ for teenagers to learn to do chores. 

A. wrong    

B. important    

C. interesting    

D. boring

3. Li Ting doesn't______.

A. do chores on weekends    

B.  go to school on weekdays

C. do her homework on weekdays    

D.  have meals on weekends

4. Why did Li Ting only have instant noodles for her meals when her parents weren't at home? 

A. Because her parents didn't give her enough money.

B. Because she couldn't cook meals.

C. Because she liked eating instant noodles very much.

D. Because she didn't enjoy doing any chores.

5. Which of the following is NOT true? 

A. Li Ting's grandmother looked after her when her father was in hospital.

B. Li Ting couldn't do any chores.

C. Li Ting's parents love her very much.

D. Li Ting was often hungry when her father was in hospital.

多项选择题