涂打（）标记的车辆，表示禁止进入机械化驼峰。
A.0
B.@
C.1
参考答案：B
—I'd like ________ the after-school club, but I'm not sure what I should do.
—What do you like ________?[ ]
A. to join, do
B. to join, doing
C. joining, to do
D. joining, doing
不锈钢管道穿墙及穿楼板时应加装套管，其间隙不应小于（）咖并填塞绝缘物，绝缘物中不应含有铁质杂质。
A．5
B．10
C．15
D．20
