【单选题】Fick 第一定律中的负号表示扩散方向与浓度降低方向 () 。
【单选题】If you ______tired,you’d better have a rest. [ ]
【单选题】Hello, boys! You’d better have a rest and relax _____.
【简答题】赛前的训练安排应做好哪两个方面:___________、___________。
【单选题】You’d better have a talk with your friend _____, and then the misunderstanding will disappear.
【单选题】Fick第一定律中的负号表示扩散方向与浓度降低方向:
【单选题】You’d better have a look at your ().