根据句子意思,用括号中所给单词的适当形式填空。
My little cousin, Jimmy, is much __________ (slim) than before.
Today is the old couple’s _________ (forty) wedding anniversary (纪念日).
How ________ (active) they are donating money to help the sick student !
It’s ________ (correct) that some grandparents carry school bags for students
Teenagers should be encouraged to make decisions by (them).