问题 选择题

控制豌豆种子颜色是黄色还是绿色的基本单位是(  )

A.染色体

B.基因

C.细胞核

D.生殖细胞

答案

基因一个是有特定遗传信息的DNA片段,一个DNA上有多个基因,生物的某个具体性状是由基因控制的,基因是决定生物性状的最小单位.因此控制豌豆种子颜色是黄色还是绿色的基本单位是基因.

故选:B

阅读理解

阅读与回答问题(本题共5小题;每小题2分,满分10分)

请认真阅读下面短文,并根据短文内容回答问题。

Do you feel lonely when your best friend isn’t around? Here’s our advice to you ---and to all kids who feel lonely sometimes. 

It’s hard when a best friend isn’t around --- maybe because he or she moved to a different school or a different class. You may feel left out at break or lunchtime. You want to have new friends, but how do you make them? Maybe it seems everybody else already has his or her friends. But remember, there’s always room for more friends.

Start by looking around your classroom --- think about which kids you’d like to play with at break. Look for chances to say hi to them, smile, and be friendly. Offer to share something or express your appreciation (欣赏) to them. Invite someone to play with you or say, “Do you want to sit here?” in the lunchroom. When you’re at break, walk over to kids you want to play with, act friendly, and say “Hi, can I play, too?” or just join in. 

If you have trouble doing this or if you’re feeling shy, ask your teacher to help you make new friends. Teachers are usually pretty good at matching up friends. The best way to make friends is to be a friend. Be kind, be friendly, share, say nice things, offer to help ---and pretty soon, you’ll have one, or two, or even more new friends.

You might still miss that special best friend. But when you see each other, you can share something you didn’t have before he or she left. You can introduce him or her to your new friends!

(请将答案写在答题卡上)

小题1:How do you feel when your best friend isn’t around you according to the passage?

                                                                       

小题2:Why do some kids feel lonely at break according to the writer?

                                                                       

小题3:What is the best way to make friends according to the writer?

                                                                       

小题4:Why do some kids need help from teachers to make friends according to the writer?

                                                                       

小题5:What should you do if you want to make more friends? (请自拟一句话作答)

                                                                       

单项选择题 A1/A2型题