医院获得性肺炎最常见的致病菌为（）
A.革兰阴性杆菌
B.肺炎球菌
C.支原体
D.真菌
E.金黄色葡萄球菌
参考答案：A
—Why is Jim not happy these days?
—Because he is busy every day. He gets _____ school at 6:40 am and gets _____ home at 5:00 pm.[ ]
A. /, /
B. to, /
C. /, to
D. to, to
CaCO3就是菱镁石。（）
