灭火原理主要是化学中断法的灭火剂是:
A、二氧化碳
B、1211
C、泡沫
D、沙土
参考答案：B
Americans speak _, you know. [ ]
A. Chinese
B. Japanese
C. English
D. American
Do you know the girl _____ hat?[ ]
A. in a
B. in
C. on a
D. on the
