正常情况下肺通气阻力主要来自（）
A.气道阻力
B.惯性阻力
C.肺回缩力
D.肺泡表面张力
E.组织的黏滞力
参考答案：D
—I'm afraid I've messed up the room.
—________. The room needs cleaning anyway. [ ]
A. Don't mention it
B. It doesn't matter
C. I've got no idea
D. It's up to you
已知△ABC的内角A、B、C所对的边a、b、c满足（a+b）2-c2=6且C=60°，则△ABC的面积S=______．
