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
