US researchers say they have demonstrated how cells fuelled by bacteria can be "self-powered" and produce a limitless supply of hydrogen.

美国研究人员称他们已经试验成功用细菌激励来电池，做到自主激励并源源不断地产生氢气。

youdao

They have demonstrated in the clearest manner how instruments of the state can be commandeered in the interests of an individual.

他们的所作所为已经清楚表明，这个国家机构是如何强占个人利益的。

youdao

Millions of people have come from every corner of the world to make this city home and they have demonstrated before how they can pick themselves up and get on with their lives.

FORBES: Hurricane Sandy - In the Eye of the Storm

And, as I said, we will have a meeting with four countries that have demonstrated and said that they would like to join the Alliance and see how far they have gone on that path.

WHITEHOUSE: Press Briefing on NATO Defense Capabilities

One by one, a half dozen employees, who call themselves Googlers, walked on stage and demonstrated how they are putting to work the degrees they have earned at top universities to help Google improve some of its most popular products.

FORBES: Google's Young And Brainy