坠器的类型有哪几种？我国广泛采用的是哪一种？
参考答案：
防坠器的类型有木罐道防坠器、钢轨罐道防坠器、制动绳防坠器三种。我国广泛采用的是制动绳防坠器。
In those days, our ______ concern was to provide people who were stopped by the snow storm with
food and health care. [ ]
A. normal
B. constant
C. permanent
D. primary
If it tomorrow, we won’t go to the park.
A．rained
B．rains
C．will rain
D．raining
