以天然气为原料小型合成氨装置合成塔电炉可以直接引起火灾原因是（）。
A、电炉绝缘不好
B、气体超温
C、气体超压
D、汽体放空
参考答案：A
A．
B．
C．
D．
—Serina has been watching the TV series the whole night.
— ________.
A．So her parents have
B．So have been her parents
C．Her parents have been so
D．So have her parents
