常用于小麦精选的设备是（）。
A、振动筛
B、抛车
C、刷麸机
D、清粉机
参考答案：B
_____ the girl was too selfish and never thought of others, she wasn’t getting on well with her classmates.
A．Though
B．Unless
C．Since
D．Until
螺母要上满扣，一般螺栓长出螺母的扣数可在（）扣范围内
A.1~2
B.2~3
C.3~4
