致病容易困阻脾土，影响运化的病邪是（）
A.燥
B.风
C.寒
D.湿
E.火
参考答案：D
Do you have a QQ number? We can _____ each other easily on the Internet. [ ]
A. chat with
B. depend on
C. agree with
D. complain about
简述反致产生的原因与条件。
