题目内容
18．-Your Chinese is pretty good，Tom．-Thanks a lot．Because I________ it for about three years．（ ）
| A． | learn | B． | have learned | C． | will learn | D． | learned |
分析 --你的中文很好，Tom．
--多谢．因为我学中文大约三年了．
解答 答案：B．
根据for about three years可知，"大约三年"表示一段时间，表示过去的动作一直持续到现在，这里指我学中文大约三年了，应该用现在完成时态；现在完成时态的结构为have/has+动词的过去分词，故选B．
点评 判断动词的时态，要通过所给的时间状语、提示词或语境去判断动词存在的状态．
练习册系列答案
相关题目
6．---Where are we going to have a trip？
---______________________．（ ）
---______________________．（ ）
| A． | It doesn't matter | B． | It's up to you | ||
| C． | That's OK | D． | Take your time |
13．----Wow!You've bought a new bike．
----Yes．I______it for just a week．（ ）
----Yes．I______it for just a week．（ ）
| A． | bought | B． | have bought | C． | have had | D． | had |
3．We'll have a picnic near the river tomorrow it rains heavily．（ ）
| A． | until | B． | if | C． | unless | D． | when |
8．Flight MU522will take off ______ half past seven．（ ）
| A． | at | B． | of | C． | in | D． | with |