4．专家还建议青少年无论在什么情况下都不要失去信心，他们的努力不会白费的。(faith，in vain)

　　【参考范文】

　　Drug abuse among teenagers has become a concern of the public. To prohibit them from doing so, people seek various ways annually.Experts suggest that teenagers should equip themselves with knowledge and make it a routine to study hard, adding that under no circumstances should they lose faith and that their efforts will not be in vain.

[高考语篇再强化]

　　Ⅰ.阅读理解

　　There are various reasons why cancers appear to be on the increase.For one thing, though their sufferers are to be found in all age groups, cancers are particularly likely to attack persons in their middle and advanced years.Naturally, since people live longer these years, there are more cancer sufferers than before.Again, with better methods of diagnosis(诊断), doctors can more easily recognize cancerous growths that would formerly have passed unnoticed or that would have been wrongly diagnosed.It is also believed that certain habits and conditions of modern living, including heavy smoking and the pollution of the air, may leave people living in more cancer­causing conditions than before.

　　We all look forward to the day when a simple medical test can find cancer when it is still small. Researchers around the world are working on such a test．Most of their work deals with the examination of the blood.

　　Researchers in Boston have found something in the blood of cancer patients that does not appear in healthy persons.The test showed which persons had cancer and which did not.It was correct more than 90 percent of the time.

The researchers believe the test may be able to show cancer very clearly in its