斑蝥的炮制方法是（）
A.炒焦
B.滑石粉炒
C.砂炒
D.米炒
参考答案：D
I think it's difficult to go ______ the forest alone. [ ]
A. across
B. though
C. through
D. cross
移动证的有效期一般为______天。
A．1
B．3
C．5
D．7
