铜及铜合金具有优良的低温性能。通关的工作压力为2.5~6.4Mpa，最高工作温度为（）℃。
A.200
B.250
C.350
D.450
参考答案：B
The play _____ next month aims mainly to reflect the local culture. [ ]
A. produced
B. being produced
C. to be produced
D. having been produced
紧急限压阀的功用是在紧急制动时限制作用风缸的压力不超过（）。
A.440kPa
B.450kPa
C.430kPa
D.360kPa
