某碳氢化合物已知可能是烯烃或是烷烃.A hydrocarbon was known to be either an alkene or alkane.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.有时它们就难于和芳香族或烯烃的吸收峰相互区别.They ar...
I won't have him risking his neck on that motorcycle.我不会让他冒险骑那辆摩托车。I thanked him for risking his neck for me.我感谢他为我冒生命危险.We do not want people of his age mucking around risking people's lives.我们不想看到像他这个年龄的人四处闲荡...