动词时态的四种用法答:She is learning piano under Mr. Smith:她是史密斯先生的指导下学习钢琴c. 表示渐变的动词有:get,grow,become,turn,run,go,begin等。The leaves are ...When,while,before,after,till,once,as soon as,so long as,by the time,if,in case (that),unless,even if,whether,the moment,the minute,the ...