问题 单项选择题

若DNA分子中一条链的碱基摩尔比为A︰C︰G︰T=1︰1.5︰2︰2.5,则其互补链中嘌呤碱基与嘧啶碱基的摩尔比为()

A.5︰4

B.4︰3

C.3︰2

D.5︰2

答案

参考答案:B

阅读理解

When you’re feeling unhappy or forget how great you are, the following ways can make you feel good about yourself.    1. Look in the mirror(镜子) and say to yourself, “I’m special and there’s no one in the world like me. I can do anything!” It may not sound so good, but it really works!    2. Do something nice for someone. Helping others always makes you feel good.    3. Smile! Be friendly to people you meet. Try to find the good things in your life.    4.Learn something new! Do you always want to make your own room more beautiful or learn how to swim? Go for it! New jobs are fun and can make you feel proud when you finish them.    5. Stay with your family. We all need our family time. Talk with your parents or maybe even your cousin.

小题1:This passage gives            ways to make us feel good about ourselves.    

A. three              B. four                     C. five        

小题2:We may make you feel proud when we             .

A. look in the mirror   B. learn new jobs            C. are friendly to people

小题3:From the passage, we can know staying with our         is one way to feel happy.

A. parents            B. friends                   C. family        

小题4:This passage tells us how to              .

A. be happy           B. remember something       C. learn something new 

小题5:According to the suggestions, which of the following is NOT mentioned(提到) ?

A. We can smile to show“How friendly you are!” to people we meet. 

B. Failing is the mother of making the dream come true.    

C. It can make us feel happy to help others.    

问答题 简答题