救火时不要张嘴呼吸或高声呐喊，以免烟火灼伤上呼吸道。
参考答案：对
解析：不张嘴是为了不吸入有害气体或被烟呛着。
In the experiment we kept a watchful eye __________ the development and recorded every detail.
A．with
B．on
C．for
D．to
— Well, ________ I have to fetch my son in the kindergarten.
— Of course. Thank you very much for helping us. [ ]
A. may I excuse myself now?
B. let me go first.
C. I'm sorry.
D. see you later.
