题目内容
选择填空:
What are you doing? I am working ______ the maths problem.
[ ]
A. out B. on C. about D. at
答案:B
练习册系列答案
相关题目
题目内容
选择填空:
What are you doing? I am working ______ the maths problem.
[ ]
A. out B. on C. about D. at