灭火的基本方法有隔离法、窒息法、冷却法和抑制法。
参考答案：对
The students told us _____________last summer vacation.
A．where did they camp
B．where will they camp
C．where they camped
D．where they will camp
蒸汽试压时要注意低点（）。
A、排凝
B、放气
C、关闭
D、保护
