用方框中所给单词的适当形式填空,,每词仅用一次。
Teachers often tell their students about the _________ of learning how to learn.Do you know that Bill Gates gave away________ of dollars in 2010?You’d better go to bed early, or you will feel_____ in class.Think it over before you make a ________.We’re in the __________ grade now. And we should learn hard.