the professor wanted his students to let him know what the topics were before they_____A set working B set to working C set about to work D set out working其他选择错误的原因是
问题描述：
the professor wanted his students to let him know what the topics were before they_____
A set working B set to working C set about to work D set out working
其他选择错误的原因是
答
B 在学生们开始工作（实验）前， 开始去做只有B set to
答
我觉得选b.我排除的哈、set不能直接接doing.排除a 、set about 接动词ing,排除c、set out 接动词不定式,排除最后一个、