根据句意，写出括号内所给单词的适当形式。
With the                (develop) of China, we can live a better life.
Our English teacher tries her best to make her students             (interest) in her class.
The more help you give to others, the               (happy) you will feel.
Boys, enjoy                (you) at the party. Have a good day!
More and more people have realized the                 (important) of saving water.