脑脊液涂片找病原菌,是诊断小儿化脓性脑膜炎的重要依据,找菌的阳性率是
A.40%~50%
B.50%~70%
C.30%~40%
D.70%~90%
E.10%~20%
参考答案:D
Lily practises _______ the piano very hard.
A.play
B.plays
C.playing
D.played
湿邪的性质和致病特点有哪些?