抗压试块制作时,振动台振动()S
A.10~20
B.15~20
C.20~25
D.10~15
参考答案:B
- Some children can't afford ________ necessary stationary. - Let's donate our pocket money to them.
A.buy
B.buying
C.to buy
D.be bought
油车、油船卸油时,严禁将箍有铁丝的胶皮管或铁管接头伸入仓口或卸油口。在正常作业状态时,卸油管道安全流速不应大于()。
A.5m/s
B.4.0m/s
C.3.5m/s
D.4.5m/s