阅读下面短文，写出括号中所给动词的正确形式，使短文意思完整。
Mr. Johnson had a factory. He once saw on TV that animals could be taught 1 (do) some work for
people if they 2 (give) to eat. He loved the idea. He thought it would be good to have a dog look after
his house and an elephant do some heavy jobs in his factory. He bought a dog and an elephant in the market
and 3 (decide) to teach them to do some work for him. Of course, he also bought a lot of food for them.
Several months later, the dog and the elephant 4 (become) fatter and fatter, but they couldn't do any
work for him. At last, Mr. Johnson had to 5 (give) up.
1.______ 2.______ 3.______ 4.______ 5.______
