A：Hello，Bob．
B：Hello，Jerry．（81） ______ ？
A：Yes，I have．The animals in City Zoo are very interesting．
B：Really？By the way，（82） ______ ？
A：Yes，I do．It's a safe and clean place for animals．
B：I see．（83） ______ ？
A：Twice a day．
B：Twice a day？Why？
A：Because they don't have enough money to buy food for the animals．
A：What a pity!What can we do to help them？
B：（84） ______ ．
A：And then we can sell the waste paper．It's a good way to make money．And it can also help to protect the environment．As we all know，（85） ______ ．
B：Right．This way，we can save both paper and trees．