1.Only in this way can the problem be tackled properly.
2.Only when children take arduous efforts can they become successful.
3.Not only does studying in school serve academic purpose, butstudents learn how to handle interpersonal relations.
4.Under no circumstances should youngsters follow negative informationon mass media blindly.
5.So valuable is water that we cannot afford to waste it.
6.Nowadays, most dangerous for youngsters is the tendency to indulgein playing PC games.
1.It is for the benefit of maintaining the ecological balance thathuman beings ought to protect the endangered animal species.
2.It is not until people suffer from some fatal diseases such as SARSand AIDS that they are becoming aware of how significant it is for thegovernment to invest more money in medical care.
1.Studies show that juvenile delinquency rates are twice as high foryoungsters from single-parent families as for those intraditional households. (同级比较)
2.Generally speaking, people in modern times enjoy less leisure timethan they did previously. (比较级)
3.Compared with those with different abilities, children with intelligencedo more well in their school work and intelligence tests.
4.Contrary to pop stars, other professionals like doctors and teacherscreate the true value for their society.
5.Air is to human what (as) water is to fish.
1.Computers, most important of all, create wide communication aroundthe world. 最重要的是，计算机在世界范围内建立了广泛的'交流。
2.Providing more parking areas, in the long run, has proved to be apractical way out in many large cities in the world.
3.Observing local culture, consciously and unconsciously, can reducethe chance of offending the locals, or it will lead to the embarrassment andeven conflict.
4.Space exploration, some people believe, will bring some unexpecteddiscoveries.
1.Violent films can do harm to young people, because they containsnumerous negative information.
2.Human beings are chiefly responsible for wild animalextinction.
3.We should attribute (ascribe)medical advances to the animals whichdo substantial contributions to the experiment.
4.Because of overpopulation, water shortage has become one of the mostserious problems.
5.Owing to the fierce competition in today’s world, a great many young peoplefind themselves under great pressure.