问题 问答题 简答题

逐次比较式、并联比较式和积分式A/D转换器各有什么特点?

答案

参考答案:

逐次比较式A/D转换器转换时间与转换精度比较适中,适用与一般场合。积分式A/D转换器的核心部件是积分器,速度较慢,但抗干扰性能力强,适用于在数字电压表类仪器中采用。并行比较式A/D转换器,转换速率可以达到很高,但抗干扰能力差,由于工艺限制,其分辨率一般不高于8位。适用于数字示波器等要求转换速度较快的仪器

阅读理解

Running is becoming popular these days. Many of us run for our health. Doctors say many of the health problems come from these bad habits: eating too much, drinking too much, smoking too much and not having enough exercise. Doctors tell us, "Eat less, don't smoke, and exercise more."

Running is good exercise because it helps build a strong heart. It also helps most people lose weight. One 68-year-old woman runs three times a week. She runs to lose weight. "I love to eat," she says.

Running is good for our health in other ways, too. Many runners say running makes colds and other small health problems go away. "Running is my doctor," says one man.

Running can also help people to relax. So today men and women of all ages enjoy running.

小题1:What bad habits do the health problem come from?

A.Eating too much.

B.Drinking too much.

C.Smoking cigarettes and not having enough exercise

D.All the above(以上所有)小题2:What do doctors tell us to keep healthy?

A.Eat less,don't smoke and exercise more.

B.Eat more,drink more and sleep less.

C.Eat less,drink less and sleep less.

D.Smoke a lot and exercise more.小题3:The underlined word means ______________ in Chinese.

A.疾病

B.体重

C.速度

D.健康小题4:The third paragraph shows____________.

A.running helps people to relax

B.people who like running have many healthy problems

C.running helps build a strong heart.

D.people who like running have fewer healthy problems小题5:The writer mainly tell us ________

A.how to run

B.running is a good way to keep healthy

C.how to lose weight

D.running is better than doctors

单项选择题