Dr Mohan already knew, from previous work, that pine-wood biochar is an effective agent for stripping lead from water.

从之前的研究中，Mohan博士已经知道了松木生物炭是一种有效的铅脱除剂。

The British secret service agency MI5 has released files which throw new light on the activities of one of its most effective double agents in the Second World War.

近日，英国谍报机构“军情五处”发布的文件进一步揭示了二战中该机构最得力的一名双料间谍的活动。