I will mark everything you say.It is helpful to the English learners.A. upB. downC. outD.

问题补充：

I will mark everything you say.It is helpful to the English learners.

A. up

B. down

C. out

D. off

答案：

A. up

(答案→)B. down

C. out

D. off

解析：mark up“提高；标记”； mark down“记下”； mark out “划出(界线、范围)”；mark off“划出，划开；区分”。由句意可知，B项符合题意。