登革热的传播媒介是（）。
A.蚊
B.人虱
C.鼠蚤
D.恙螨
E.蜱
参考答案：A
It is not enough only_______the rules of grammar if you want to learn English well.
A．keeping in the mind
B．to keep in mind
C．to keep in your mind
D．keeping in your mind
什么是纠正措施？什么是预防措施？请举例说明？
