流行性斑疹伤寒的传播媒介是()
A.人虱
B.鼠蚤
C.恙螨
D.蜱
E.蚊
参考答案:C
Every morning I get up at 6:00 because I have two dogs ______ at the door for me to take them out for the routine walk.
A.to wait
B.wait
C.waited
D.waiting
有人认为,口语交际与听说训练没有区别。你有什么看法?