The boys are sweating all over. They().
A. must be working
B. must have been working
C. may be working
D. must work
出自:国家开放大学管理会计案例

完成拼图验证

按住下方滑块,将拼图拖到缺口处后松开。

拼图背景,将小拼图拖到缺口处
向右拖动滑块