确诊白血病的最重要手段是（）。

A.外周血检查

B.浆膜腔穿刺

C.骨髓检查

D.腰椎穿刺

E.以上都不正确

— （）
—I'm suffering from a stomachache.

A. Are you feeling better

B. What's trouble with you

C. Is there wrong with you

D. What's the matter with you