Last Sunday, a group of pupils talked happily a loud voice as they went to the countryside bike.
A:by; by
B:in; on
C:in; by
某中学在期中考试中设置了无人监考的“文明考场”,考前学生要签订考试承诺书。这场考试虽然没有监考老师,但秩序井然。据此回答小题