乳油在硬水中使用效果更好。
参考答案:错
It looks as if they were going to us 3,000 dollars for the concert hall.
A.want
B.charge
C.demand
D.cost
在工艺流程管线中,绿色管线代表()。
A、压缩空气
B、水线
C、氢气
D、氧气