题干
The student had no choice but _____ his teacher ____ the mistake he had made.
A：to apologize to , for
B：to apologize, for
C：apologizing for, to
D：to apologize for, for
答案(点此获取答案解析）
A
用可以是氧化剂、还原剂、既是氧化剂又是还
原剂、既非氧化剂又非还原剂等。下列反应与Br2+SO2+2H2O=H2SO4+2HBr相比较，水的作用不相同的是