骨嗜酸性肉芽肿好发于()
A.颅骨
B.骨盆
C.肋骨
D.脊柱
E.股骨
参考答案:A, B, C, D, E
— _____ do you surf the Internet, Kate? — Not often, twice a month.
A.How long
B.How old
C.How often
D.How many times
触电分为()和()两种形式