新投入的分接开关，在投运后（）年或切换5000次后，应将切换开关吊出检查。
A.1一2
B.2一3
C.3一4
D.4一5
参考答案：A
与宫颈癌的发生密切相关的病毒是（）.
A.HBV
B.HPV
C.HSV
D.HIV
E.HCMV
_____ he is still young, _____ he can speak English well. [ ]
A. Although, but
B. But, although
C. Although, /
D. /, but
