消除应力退火在保温一段时间后,随炉冷却或冷却到()℃后出炉,在空气中冷却。
A.100~200
B.200~300
C.300~400
D.400~500
参考答案:C
水封是隔断煤气来源的可靠装置。
When we finally ______ to get all the work done, we were so exhausted that we simply felt like lying down and having a good sleep.
A.tried
B.managed
C.succeeded
D.attempted