题目

以下对催化剂及其作用的理解正确的是（    ）   A．能增加生成物的质量      B．可加快或减慢反应的进行   C．只能加快反应            D．不用催化剂反应不能进行  答案：B解析:略   ― I’m sorry to bother you at this time of night. ― _________. It’s just so happened that I’m not engaged right now. A. All right           B. That’s OK                C. You’re welcome      D. Please don’t be bothered