防坠器分为三种：（）防坠器、（）防坠器、（）防坠器。
参考答案：木罐道；钢罐道；制动绳
熏烟型气象条件出现在( )。
A．日出前
B．日出后
C．中午
D．晚上
Activities in our school __________ sports, language learning and music _________.
A．include; also
B．including; too
C．cover; as well
D．covers; too
