It's getting darker and darker. I am afraid a heavy rain is ______.
【正确答案】 D
【答案解析】天越来越黑了。恐怕一场大雨即将来临。A impacting“对……发生影响,撞击” B.impeaching“控告,告发”C.impeding“阻碍,阻止”D.impending“即将发生”