以下一定能说明化学平衡发生移动的是( )。
A.正、逆反应速率改变
B.加入催化剂
C.增大压强
D.反应转化率的改变
答案:D
探究植物对空气湿度的影响
(2)比较草地组和灌木丛组两组数据能说明什么问题?
—That T - shirt with Yao Ming's picture on it _________ belong to Jack. He likes Yao Ming very much.
—No, it _________ be his. He doesn 't like black T - shirts. [ ]
A. can; can't
B. must; can't
C. must; mustn't