5.speculation n.投机活动

例句：He ventured on a rash speculation.

他进行鲁莽的投机。

A lucky speculation in the stock market put him on easy street for the rest of his life.

股票市场上一次幸运的投机使他余生过着舒适的生活。

6.intractable adj.难对付的, 难解决的

例句：It emerged as the most intractable issue of our era.

它成了我们时代最难解决的问题。

7.unilaterally adv.单方面地

例句：In international custom,a nation that unilaterally breaks contracts must make good the damage.

根据国际惯例,某国单方面撕毁合同必须赔偿损失。

8.arduous adj.艰巨的;艰难的；艰苦的；费力的;困难的

例句：The refugees made an arduous journey through the mountains.

难民们艰难地越过高山。

9.conceal vt.隐瞒,隐匿,隐蔽,隐藏

1.The Libyan government insists that its troops are not killing civilians,and are only taking up defensive positions around towns like Zawiya.

insist用法

insist【用法一】 v. 坚决要求；坚持要；一定要

例1：we insisted on his apology.

我们要他赔礼道歉。

例2： she insisted on seeing us home.

她坚持要送我们回家。

例3： i insisted on their arriving there ahead of time.