I heard him______ outside.
#50192
A
sang
B
to sing
C
singing
D
sings
推荐题目
Julia Morgan has just finished ____ her last movie.
#49926
A
make
B
makes
C
made
D
making
Sorry,we don’t allow ________ in the lecture room.
#48947
A
to smoke
B
smoke
C
smoking
D
to smoking
 Lucy decided _____ a new computer. 
#49105
A
buy
B
to buy
C
buying
D
bought