Where he work?[ ]
A. do
B. does
C. is
答案：B
We ____ there when it ____ to rain. [ ]
A. were getting-would begin
B. were about to get-began
C. had got-had begun
D. would get-began
炉渣脱S的化学反应式（CaO）+（FeS）=（CaS）+（FeO）。
