阅读短文，从方框中选择适当的词并用其正确形式填空，使短文意思通顺、完整。请将答案写在短文后相应题号的横线上。每空限填一词，每词限用一次。方框中有两个词是多余的。

need  remember  never  like  water  do  another  mistake  often  friendship  good  rich

Graduation is coming! Many students are leaving school. What are they taking with them? A lot of things for sure, but the most important thing is ______.
We asked some teachers to give us the last lesson. The lesson is proverbs about friends. Older people _ ____ teach proverbs to younger people. Every culture has proverbs. They are short and easy to ___ __.
There is a German proverb which says, “Friendship is a plant we must _____.” It means that we need to take care of friends ______ taking care of a garden. “Only your real friends will tell you when your face is dirty.” is _ ___ proverb from Japan. It means that only _____ friends tell you when you are making a _______.
My grandfather told me, “Nobody is so _ ____ that he can throw away a friend.” Everyone ______ friends. Be good to them.
Goodbye, friends! Don’t forget us!