问题 单项选择题

与十进制数1023等值的十六进制数为( )。

A.3FDH

B.3FFH

C.2FDH

D.3FFH

答案

参考答案:B

解析:十进制转成十六进制的方法是"除十六取余"。

阅读理解

阅读理解。

    A smile will tell people around you that you are a kind and friendly person. However, many people don't

smile because they think they have ugly teeth. For example, one of my classmates, Mile, doesn't have very nice

teeth, so thatis why he seldom opens his mouth.he even says that he has lost cofidence because of his teeth.

So it is very important for us to look after our teeth. In fact, a lot of people have this problem. Some people

inherit teeth problems from their parents, while others'teeth are damaged because of bad habits, like heavy

smoking, eating too much sugar or not brush-ing teeth often. If your teeth are in bad shape, you should see

a dentist and ask for help. They can help improve your teeth and tell you how to take care of then.

    Smiling can help you to feel more confident and make other people think of you as a more friendly person.

If you want to keep healthy, you should not only smile but also laugh. An Indian doctor called Kataria said

that young children should laugh about 300 times a day, wile adults should laugh between 7 and 15 times a

day. So please take this chance to smile and laugh now!

1. What has made Mike lose his confidence? [ ]

A. His bad habit.

B. His bad teeth.

C. Not smiling.

D. Eating too much sugar.

2. Many people don't smile because           . [ ]

A. they don't like smiling

B. they think they are ugly

C. their teeth are not beautiful

D. they can't open their mouths

3. What can a dentist do according to the passage? [ ]

A. A dentist can tell you how to improve your bad teeth.

B. A dentist can help you to take care of your bad teeth.

C. A dentist can tell you how to brush your teeth.

D. Both A and B.

4. If you want to keep healthy, you had better            . [ ]

A. not smile often

B. laugh all the time

C. neiter smile nor laugh

D. smile and even laugh often

5. How many times should a child laugh every day in doctor Kataria's opinion? [ ]

A. Either 300 or 30 times a day.

B. Between 7 and 15 times a day.

C. Around 300 times a day.

D. Only 30 times a day.

不定项选择