天空是蓝色的原因是（）。
参考答案：
散射
----You failed again in the maths exam yesterday.
----Don’t tell Dad about it; if he knows that ,I’m dead.
A．as well as
B．as good as
C．as possible as
D．as far as
内关的特定穴性质是（）。
A.原穴
B.络穴
C.荥穴
D.八会穴
E.八脉交会穴
