承包人更换项目经理应事先征得发包人同意，并应在更换（）d前通知发包人和监理人。
A．14
B．28
C．30
D．60
参考答案：A
Cynthia is not ashamed of what she does, ____ she ends up doing something wrong. [ ]
A. as though
B. in case
C. even if
D. for fear
CNG中氧含量必需小于（）。
A、1％
B、0.5％
C、0.1％
D、0.7％
