about the health of Kim Jong Il. The North Korean leader remained out of sight for a number of significant occasions, including the launch of a long-range rocket that angered the international community.

VOA: standard.2009.12.30

So to figure out bonding electrons, -- what we take is that number 18, which is our total number of electrons we need to fill valence shells, and we subtract it from our number of valence electrons, which is 10.

那么为了找出成键电子，我们将十八，也就是填满所有价壳层,所需要电子的总个数，减去我们所有的价电子的个数，也就是十。

麻省理工公开课 - 化学原理课程节选

There were probably a number of firms that, over that ten-year period, went out of business.

在这10年间,可能有很多企业已经破产

耶鲁公开课 - 金融市场课程节选

Critics say this leaves the window open to push the Maoist party, which won 40 percent of the seats in last year's election, out of the picture - paving the way for any number of smaller parties to bid for the prime minister seat.

VOA: standard.2009.05.10

We're talking about a vast number of trees that are taken out of forests every year, which are contributing to that one-fifth of global emissions that comes from deforestation and contributing to the loss of wildlife, contributing to the loss of people's livelihoods and contributing to the loss of revenue from governments."

VOA: standard.2010.07.28