问题 单项选择题

Internet体系结构具有良好扩充性的主要原因在于它______。

A.基于客户机服务器结构,具有单向依赖性

B.基于树型结构,具有层次性和单向依赖性

C.基于环型结构,节点之间无依赖性

D.基于星型结构,节点之间无依赖性

答案

参考答案:B

解析: 在整个体系结构上,Internet采用的是树型组织方式,最大的特点是具有层次性和单向依赖性,易于扩充。

阅读理解

There have always been a lot of commonly believed but false ideas about being fat and doing exercise. Some people believe that they can’t help putting on weight as they get older, while others hold that if they stop exercising, their muscles will turn into fat. Here are some more myths:

I’ll never lose weight --- I come from a fat family

Wrong! While we can’t change the body type we are born with, we can’t blame our genes for making us fat. There’s plenty of evidence that fatness runs in families, and the main reason is that they share the same habits of eating too much and exercise too little.

I am fat because I burn calories slowly

Wrong! Fatness is not caused by a slow metabolism(新陈代谢). If fact, although fat people consume more energy that slim people, they also fail to realize how much they eat! Keeping a diary can help you work out your daily food intake more accurately.

Exercise is boring

Wrong! Anything will become boring if you do it repetitively. The key is to develop a balanced and varied program that’s fun as well as progressive. If you enjoy a Sunday walk, take a different route. If you do Yoga, try a tai chi class. If you like swimming, set yourself a distance or time challenge.

No pain, no gain

Wrong! Exercise is not meant to hurt. Indeed, pain is your body telling you something’s wrong, and continuing to exercise could lead to serious injury. You may experience mild discomfort as you begin to exercise regularly, but this your body adapting to the positive changes in your lifestyle and the aches should disappear relatively quickly. If you don’t, rest and seek medical advice.

小题1:What does the author think about being fat?

A.It is the family genes that make people fat.

B.People are fat because they consume too little energy.

C.A diary of exercise can prevent people from becoming fat.

D.It is the consequence of people’s unbalanced lifestyle.小题2:According to the author, how can we make exercise more interesting?

A.By taking varied exercise.

B.By choosing simple exercise.

C.By doing regular exercise.

D.By sticking to outdoor exercise.小题3:What is the author’s opinion about “No pain, no gain” in exercising?

A.Keeping fit is essentially a painful experience.

B.Exercise should be stopped if continuous pain is felt.

C.Pain in exercise is a precondition for reaching your goal.

D.Getting used to pain leads to positive changes in your body.小题4:What is the purpose of the passage?

A.To declare the importance of keeping fit.

B.To clarify some misconceptions about fatness and exercise.

C.To confirm what has long been believed about keeping fit.

D.To explain some medical facts about being fat and doing exercise.

单项选择题