轴承温度计是测量风压用的。
参考答案：错
B．周期可能是0.4s
C．波速可能是6m/s
D．波速可能是5m/s
---What are you going to do this weekend ?
--- Well, we’ll clean up the city parks ________ it rains..
A．if
B．until
C．while
D．unless
