题干
--- Do we have to finish our homework this afternoon?
--- Yes, you .
A：must
B：can
C：may
D：need
答案(点此获取答案解析）
A
--- Do we have to finish our homework this afternoon?
--- Yes, you .
A：must
B：can
C：may
D：need
Si + 2CO
SiCl4 ③SiCl4 + 2H2
Si + 4HCl，其中反应①和③属于（ ）