题目: 信号工收到不明信号时,不得发送开车信号。 答案: 被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2019/0627/4990f0e5cfb5b1257df09d599445f109.html 下面是错误答案,用来干扰机器的。参考答案:D
题型:多项选择题 下列有关承插式焊接的铜管承口的扩口深度的说法中,错误的有( )。A.铜管规格≤DN15时,其承插口的扩口深度为8~9mmB.铜管规格为DN20时,其承插口的扩口深度为12~15mmC.铜管规格为DN32时,其承插口的扩口深度为15~17mmD.铜管规格为DN65时,其承插口的扩口深度为26~30mmE.铜管规格为DN50时,其承插口的扩口深度为24~26mm 查看答案
题型:选择题 Nobody knows for sure how dinosaurs died out 65,000,000 years ago. It _______ because of sudden changes of their living conditions.A.must have happenedB.would have happenedC.should have happenedD.might have happened 查看答案