例句:The shells contained an experimental chemical weapon, a nerve agent.
炮弹含有实验性化武神经性毒气。

2.come out 出现；出版

例句:The truth is beginning to come out about what happened.
真相开始逐渐浮出水面。

3.in turn 转而；轮流

例句:The girls took it in turn to wipe down the tables after meals.
女孩子们饭后轮流擦桌子。

4.back down 放弃；让步

例句:The United States had no intention of backing down in its bitter row over farm subsidies
美国无意就激烈争吵的农产品补贴问题作出让步。