. ________ on the subject for half an ho
题型:选择题
问题:
.
________ on the subject for half an hour, Liu Ying suddenly stopped.
A.To be worked
B.To work
C.Having worked
D.Having been worked
.
________ on the subject for half an hour, Liu Ying suddenly stopped.
A.To be worked
B.To work
C.Having worked
D.Having been worked