问题详情

21. Now many animals can do some simple jobs that are done by human beings.

22. The writer says that 8t a circus we can see animals doing cIever tricks.

23. The trainer usually gives the animal a piece of candy or fruit after it has done the trick.

24. The reward in the passage means "attention paid to a good behavior".

25. Many animals may be trained to do simple jobs if they know who their trainers are.

26. Geese can be used to guard a house.

27. When the pigeon sees a ball which looks different from the others , it makes a noise.

28. Trainer usually spends 40 days or so training a pigeon to inspect sm811 steel balls.

29. An ape is a large monkey.

30. Scientists believe apes may drive buses one day.