阅读下面短文,按照句子结构的语法性和上下文连贯的要求,在空格处填入一个适当的单词或使用括号中单词的正确形式填空。Passage 1Children sometimes get sick(生病) and need to go to hospital. Some of 1._them_ (they) have to stay there for a few days. 2._It_ is not good for them to think about their sickness all day long. They need some other things to think about. So people ask animals 3._for_ help. In some places, workers from zoos often take animals 4._to_visit_ (visit) children in hospital. They may bring a little dog or a cute monkey with them.