根据所给汉语注释，写出各单词的正确形式。
小题1:Shanghai is one of the __________(热闹的) cities in China.
小题2:In the past, cats were good at ________（抓捕）mice.
小题3:The air pollution in this area caused the ________(死亡) of many trees.
小题4:Reading is _______(有帮助的) to improve your writing skills.
小题5:Linda __________(拒绝) to help me with my homework last week.
