必要时可以把它当作武器.At a pinch it can be used as a weapon.必要时, 他们愿为国捐躯.They were ready to die , if necessary, for their country.他们不怕应对这些问题，也不怕必要时来一番激烈的争论。They are not afraid to tackle the issues or let the sparks fly when necess...
菲尔信心十足地走向前去,本却踌躇不定.Phil walked forward confidently but something held Ben back.踌躇了半天, 他终于直说了.After a long hesitation, he told the truth at last.他踌躇了一会儿.He paused for a moment....
在较高的烯烃情况下, 高能的中间物稳定作用更易出现.With the higher olefins, stabilization of the energetic intermediates occurs more easily.我们实际上遇到介乎此两个极端的中间物.We would actually encounter a mean between these extremes.这样可以得到最高产率的反应中间物,即目的产物.This ...