引起霍乱泻吐的原因是
A.内毒素B.肠毒素C.细菌的侵袭力D.菌群失调E.细菌的直接作用
参考答案:B
— are you leaving for Hong Kong?
—I'm flying there. [ ]
A. Why
B. How
C. What time
D. Where
有助于幼儿正确的掌握字音的儿歌是()
A.谜语歌
B.饶口令
C.游戏歌
D.字头歌