Complete the sentences with the correct form of the words in capitals

Complete the sentences with the correct form of the words in capitals.\
1.Thanksgiving is a _______ festival held in the USA. (SEASON)
2.Biogas is thought to be clean, safe and _______. (EXHAUST)
3.That’s a very _______ T-shirt that John is wearing. (TREND)
4.Car exhaust is the main reason for the city's ______. (POLLUTE)
5.The office looked very _______ with its Christmas tree. (FESTIVAL)