婴儿痉挛症的临床特点是什么?
参考答案：
1岁前发病，3～7个月为发病高峰，表现整体性肌阵挛发作，智力低下，EEG高峰节律紊乱；病因多样，一般预后不良。
____________ is playing with ____________ ball.[ ]
A. he; his
B. She; his
C. He; his
试述开放性气胸的病理生理？
