用所给动词的适当形式填空。 1. There ______ (use) to be animals in the forests. 2. I don't think no zoos are______ (suit) for animals to live in. 3. We can see that the animals are _ (keep) in tiny cages and can hardly move at all. 4. I have never __ (see) such a big elephant like that. 5. I urge all of your readers (visit) our wonderful zoo soon. |