问题:
Sit down, Emma. You will only make yourself more tired, _____ on your feet.
A. to keep
B. keeping
C. having kept
D. to have kept
Sit down, Emma. You will only make yourself more tired, _____ on your feet.
A. to keep
B. keeping
C. having kept
D. to have kept
A. to keep
B. keeping
C. having kept
D. to have kept
参考答案: