---Do you still smoke heavily?       --- No. In fact, it is two years since I __

题型：不详难度：来源：

---Do you still smoke heavily?       
--- No. In fact, it is two years since I ____.  
A. have stopped smoking               B. smoked   
D. began to smoke                    D. started to smoke

答案

B

解析

考查since结构。it is two years since I ____。ince后面跟延续性动词，表示在动词动作结束后已经两年了。即我不吸烟已经两年了，吸烟这一动作发生在过去，所以用一般过去时态。选B。