用括号内所给单词的适当形式填空。
This _________(feel) makes him upset all day and night.
Mother lets Michael ___________ (not watch) TV all day because the final exam is coming.
He has a lot of trouble ___________ (work) out the problems.
I love the opera, Cats. It’s so _________ (fun).
Mrs. Green seems (worry) because his son is ill.