运动神经元病中最不易受累的肌肉是（）

A.四肢骨骼肌

B.躯干肌

C.呼吸肌

D.肛门括约肌

E.眼外肌

All ________is needed for life on board the submarine comes from the ocean.

A．/

B．what

C．that

D．which