在起升机构减速器高速轴端安装（）及相应（），以便在断电时实现制动。
参考答案：制动轮；制动器
—What ____ does she like?
—Baseball. She ____ every day. [ ]
A. exercise; exercise
B. exercise; exercises
C. exercises; exercise
D.exercises; exercises
避雷针一般可用（）制成。
A.镀锌圆钢
B.铝管
C.铜管
D.钢管
