They’ve already made it clear to us that they will never ____ to any difficulty.

A．give up

B．give out

C．give in

D．give away

属于芽胞厌氧菌的是（）

A.绿脓杆菌

B.脆弱类杆菌

C.肺炎双球菌

D.产气荚膜杆菌

E.金黄色葡萄球菌