急性咽后脓肿的致病菌为（）
A.乙型链球菌
B.链球菌、葡萄球菌
C.乙型溶血性链球菌
D.白喉杆菌
E.结核杆菌
参考答案：C
Though he is busy, he is very _____ and makes a telephone call to his parents from time to time and tries his best to spare some time to visit them.
A．constant
B．considerate
C．considerable
D．conscious.
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