下列不是急性气管-支气管炎的常见致病原的是（）
A.腺病毒
B.肺炎球菌
C.支原体
D.MRSA
E.流感嗜血杆菌
参考答案：D
振动式密度计的结构有哪些组成？
He tried many times to sneak across the border to a neighboring country,（）caught each time.
A. having been
B. only to be
C. always being
D. unfortunately
