辨识句中的一处错误，答案填写Ａ，B，C，D字母。 Each of the students in the accounting class has to type their own research A B C D paperthis semester.

A.10
B. 11
C. 12
D. 13

A、抗震等级
B、混凝土强度等级
C、钢筋牌号为HRB400
D、钢筋生产厂家