After ______ his exercises,he left the classroom to play with his friends.
After ______ his exercises,he left the classroom to play with his friends.
A.hand in
B.handing in
C.giving in
D.handed in
答案及解析： B
After ______ his exercises,he left the classroom to play with his friends.
A.hand in
B.handing in
C.giving in
D.handed in
答案及解析： B