高等教育 /
(单选题) The trainer usually gives the animal a piece of candy or fruit _______.( )
A、before it plays a trick
B、when it is hungry
C、after it has done the trick
D、when it starts to play a trick
A、before it plays a trick
B、when it is hungry
C、after it has done the trick
D、when it starts to play a trick
参考答案：
佳题速递：