BC140充电器可被插入到（）的手柄为其充电。
A.特殊
B.特种
C.PD140R
D.BC150
参考答案：C
Greedy _______ the opportunity to prove his ability, he took up the without any hesitation.
A. with B. about C for D. of
锅炉水中pH为（）时，磷酸钠除硅的效果较好。
A.11-13
B.9-10
C.6-8
D.2-3
