对尺寸要求高的焊接件,应考虑焊件的装配间隙和焊接收缩量。一般焊接构件角焊缝的装配间隙______mm。
A.为0~1.5
B.≤2
C.≤3
D.≤4
参考答案:B
中子具有很强的穿透能力。
Which statement about the preliminary design stage of a software development project is true ______.
A.The preliminary design is an internal document used only by programmers
B.The preliminary design is the result of mapping product requirements into software and hardware functions
C.The preliminary design of the product comes from the requirement specification
D.The developers produce the preliminary design by defining the software structure in enough detail to permit coding