Chen Long, a man from Jingzhou, has ____ (go) through a lot before he won the first gold medal of the 2016 Olympic Games.
正方体ABCD-A1B1C1D1中,M、N分别为棱AB,DD1中点,则异面直线A1M与C1N所成的角是( )
下列句子停顿划分错误的一项是( )