Supply the correct form of the words in brackets to complete the following sentences .
1. The accident happened because he drove ....... ( care )
2. Air .......... is one of the problems that people have deal to with . ( pollute )
3. Traditional ............ are a good source of fun and entertainment. ( celebrate )
4. You should buy this book. It's very ........... ( inform)
5. (Tradition) ............ people eat sticky rice cakes at Tet .