Give the correct form of the word given to fill in the blank

Section VI. Give the correct form of the word given to fill in the blank.

1. Recently health foods have increased in .................... (popular)

2. I am .................... he will succeed in his career. (confidence)

3. The water in this area is .................... and should not be drunk. (pure)

4. Alison’s .................... made it hard for her to speak in public. (shy)

5. The police are interested in the sudden .................... of the valuable painting. (appear)