诊断胸腔积液最重要的依据是（）

A.胸痛

B.结核菌素试验阳性

C.X线检查发现左侧肺部有大片状阴影

D.患侧胸部呼吸运动减弱

E.胸腔穿刺抽出液体

Speaker A: I think tourism is a great way of helping the economies of developing countries.
Speaker B: ().

A. Yes, I agree. I myself like nothing better than travel.

B. Maybe. Can you explain the advantage of developing tourism

C. Well, in my opinion, the governments of developing countries should create more job opportunities for their people.

D. Yes, it is. Without tourism, those countries would be much worse off.