—I left my handbag on the train, but luckily someone gave it to a railway official.

—How unbelievable to get it back！I mean, someone ________it.

A．will have stolen

B．might have stolen

C．should have stolen

D．must have stolen

容器施工动火时，必须按规定吹扫干净，保证氧气含量为（）才可动火。

A、≦20.5%

B、≦22%

C、≦25%