煤气加热炉停煤气时，应先关闭所有烧咀，然后停风机。
参考答案：对
The number of teachers in our school _______ greatly increased last term.
A number of teachers in this school _______ from the countryside.[ ]
A. was; is
B. was; are
C. were; are
D. were; is
包车单位在始发站延期使用，如何核收费用？
