活动轿厢超载保护装置是在活动轿厢的底盘与轿厢架固定底盘间,垫以一定数量特殊要求的(),用橡胶垫变形来测量轿厢重量。
A.橡胶垫
B.弹簧
C.传感器
D.木块
参考答案:A
.---____ did you leave the classroom? ---____ I saw my daughter sit down and read her book.
A.How long; After
B.When; Until
C.How long; Until
D.When; After
交换局开关电源系统严禁开启()功能。