在线检验是在运行条件下对在用工业管道进行的检验,在线检验每年至少两次。
参考答案:错
解析:在线检验是在运行条件下对在用工业管道进行的检验,在线检验每年至少一次。
Software maintenance is to do necessary modification,supplenemt, and completeness during software life circle. Among the following vary kinds of maintenance,which one has the maximum workload in a general way
A. relevance maintenance
B. completeness maintenance
C. correctness naintenance
D. other kinds of maintenance