如图a所示，圆柱体一侧作用于两种液体，上部分油的密度ρo=800kg／m3，下部分为水。巳知圆柱体长L=10m，直径D=2m，

The author concludes that school rules to forbid smoking__________ ．

A.should be introduced although it might prove ineffective

B.should be introduced because it was done at the school he studied

C.should not be introdticed because it may cause rebellion

D.needn’t be introduced as long as the teachers don’t smoke

The writer concludes that potential offenders could be helped by ___.

A.spending more time at school

B.more encouragement at school

C.more activities outside school

D.stricter treatment from teachers

What is NOT mentioned in the text on the writer's way to school？

A．the writer saw some Russian soldiers drilling

B．the writer was stopped by a person

C．the writer saw many people reading a notice

D．the writer saw many people quarrelling about something

______ The writer concludes that the word laziness is sometimes applied incorrectly.

A．T

B．F

non-smokers they are more rebellious, their work deteriorates as they move up school, they are more likely to leave school early, and are more often delinquent and sexually precocious.Many of these features can be summarized as anticipation of adulthood.

There are a number of factors which determine the onset of smoking, and these are largely psychological and social.They include availability of cigarettes, curiosity, rebelliousness, appearing tough, anticipation of adulthood, social confidence, the example of parents and teachers, and smoking by friends and older brothers and sisters.

It should be much easier to prevent children from starting to smoke than to persuade adults to give up the habit once established, but in fact this has proved very difficult.The example set by people in authority, especially parents, health care workers, and teachers, is of prime importance.School rules should forbid smoking by children on the premises.This rule has been introduced at Summerhill School where I spent my schooldays.

There is, however, a risk of children smoking just to rebel against the rules, and even in those schools which have tried to enforce no smoking by corporal punishment there is as much smoking as in other schools.Nevertheless, banning smoking is probably on balance beneficial.Teachers too should not smoke on school premises, at least not in front of children

1、Which of the following is a common characteristic of young smokers？

A、Disobedience

B、Laziness

C、Lack of intelligence

D、Vanity

2、Which of the following is NOT true according to the passage？

A、Some children start to smoke out of curiosity

B、Many children start to smoke because they want to appear mature.

C、In order to have fewer children smokers, parents, teachers and health care workers should not smoke.

D、It is not as difficult to prevent children from starting to smoke as to dissuade adults from smoking.

3、The writer concludes that school rules to forbid smoking().

A、should be introduced, for it really works at the school where he once studied.

B、should not be introduced, for it may cause disturbance.

C、should be introduced though it may not work effectively.

D、needn't be introduced as long as teachers don't smoke in front of children.

4、The author's attitude towards his writing is().

A、objective

B、emotional

C、critical

D、indifferent

The writer concludes that tourism in the Third World ______.

A．produces only limited economic benefits

B．amounts to a present-day form. of colonialism

C．is developed at the expense of other industries

D．will bring prosperity to it only in the distant future

The writer concludes that tourism in the Third World ______.

A．produces only limited economic benefits

B．amounts to a present-day form. of colonialism

C．is developed at the expense of other industries

D．will bring prosperity to it only in the distant future

In the writer's opinion, a good stage school should ______.

A．produce star performers

B．train pupils in language and performing arts

C．provide a general education and stage training

D．help pupils improve their study skills

According to the passage, which of the following is fight？

A．The writer's teacher was very strict.

B．The writer was very clever.

C．The writer got to school early that morning.

D．The writer got to his desk in the noise without being seen.

The writer in this article concludes

A．that the saving and spending patterns in Great Britain are better than those in America

B．that the consumers always expect the price to rise a bit at sessions

C．that maintaining stable prices is a correct business policy

D．that people's income and consumption level are interrelated