Although they contain only a small fraction of all galaxies, rich clusters provide a powerful tool for the study of galaxy formation, dark matter, large-scale structure and cosmology. Numerous attempts have been made to investigate clusters of galaxies in last decades.

Since 1975, when Rubin carried out her pioneering study, there have been numerous attempts to identify and describe strategies employed by good language learners and poor language learners or by ESL learners and EFL learners.

自从1975年Rubin进行她的开拓性研究以来，许多研究者试图确认和描述成功学习者与不成功学习者，或且二语学习者和外语学习者的学习策略。

Despite numerous attempts by author, with different focal distances and camera positions, the Y-shape shadows in photographs of the poster tiger never displayed any distortion ( Fig.10).

尽管作者进行了无数次尝试，以不同的焦距和不同的相机位置拍摄，墙画虎的照片中Y形阴影绝不会消失或扭曲。

On Saturday, he tried to buy the ticket for his trip returning home on Feb 8 but failed after numerous attempts.

上周六，他试图购买一张2月8日回家的车票，但屡试屡败。

Numerous attempts have been made to hide the truth.

人们作了很多努力想掩盖事实。

Its proliferation record would make the serial nuclear mischief-makers of North Korea blush.

巴核扩散记录甚至会让成群结队的对朝鲜核活动挑拨离间者脸红。

These dodgy documents could allow mischief-makers to impersonate supposedly secure websites.

挑拨离间者可用这些虚假的许可证冒充安全网站。

From the start the Coen brothers have been clever mischief-makers, repeatedly pulling the rug from under their characters and the audience alike.

在电影《血迷宫》中，科恩兄弟从一开始就设下层层圈套，让观众不断颠覆对剧中人物的看法。

My boy is such a mischief-maker. I am at my wits'end with him.

我儿子真是个淘气包，我拿他一点儿辙都没了。

The letter had come from an unknown mischief-maker.

这封信来自一个匿名的离间者。

Oh, then you must be the self-confident Sharp-as-a-tack mischief-maker.-

噢，那你一定是那个很有自信聪明伶俐爱恶作剧的那个孩子吧。-

Man, the trouble-maker of the network ethic problem, is also capable of solving the very problem.

人既是网络道德问题的创造者, 也是网络道德问题的解决者.

The trouble-maker was booted out.

那个捣乱者被赶了出去.

It's inappropriate to say he is a trouble-maker.

说他是个闹事者是不妥当的.

He is a real trouble maker.

他真是个捣蛋鬼.

I think this new student is a bad hat.

我想这个新学生是一个坏学生。

Everyone knows that he is really a bad hat.

每个人都知道他是一个十足的坏蛋。

He was formerly a known player, but turned out a very bad hat indeed.

他从前是个有名气的选手，而结果成为一个一无所长的人。

Now I never hear talk of the wearing of a bad element'hat,'just that of a right wing'hat.'And the bad element hat is never removed.

现在也没有听到说给坏分子摘帽子的话，只是说摘右派分子的帽子，而坏分子的帽子是不摘的。

I never thought that he was such a bad hat.

我决不会想到他是如此坏的一个领导。

The gangster's friends bought off the police witness.

那坏蛋的朋友买通了警察方面的证人.