方框中所给单词的适当形式填空。(每小题1分，共5分)

spend   weigh   slow   leaf  succeed

Spring is coming and the             turn green.
If we walk            , we'll be late for the film.
--What are they doing? --They are            an elephant.
He is very happy because he has            in passing the exam.
Mrs. Smith             three thousand yuan on the gold necklace.