问题:
Peter is busy ___________ at school, but he never forgets __________ exercise every day.
A.work
B. doing
C.working
D. to do
E.work
F. to do
G.working
H. doing
Peter is busy ___________ at school, but he never forgets __________ exercise every day.
A.work
B. doing
C.working
D. to do
E.work
F. to do
G.working
H. doing
A.work
B. doing
C.working
D. to do
E.work
F. to do
G.working
H. doing
参考答案: