重度肺气肿病人可发生（）

A．呼吸性酸中毒

B．代谢性酸中毒

C．呼吸性碱中毒

D．代谢性碱中毒

E．代谢性碱中毒合并呼吸性酸中毒

We do jobs_____they need to be done and that could be early in the morning or late at night.

A．that

B．which

C．when

D．how