Richter疝()。
A.疝内容物为大网膜
B.疝内容物为小肠憩室
C.疝内容物为单个小肠肠襻
D.疝内容物为部分小肠肠壁
E.疝内容物为多个小肠肠襻
参考答案:D
Which of the following statements is correct ( )
A.The definition phase results in the Software Requirements Specification
B.Testing is optional in software life cycle
C.CASE tools can only aid in the design phase of a software life cycle
D.A change during a later phase does not require the documentation of all earlier phases to be up-dated
在氩气和二氧化碳混合气体保护焊中二氧化碳的加入量通常为()。
A、5%-30%
B、1%-5%
C、15%-30%