当r=0.2时，则决定系数为（）
A.2%
B.4%
C.10%
D.20%
E.40%
参考答案：B
— terrible weather it is!
—It is said that it will get _ later. [ ]
A. What; bad
B. What; worse
C. How; bad
D .How; worse
气力除灰系统中主要有哪些？
