题目内容：

阅读下面的短文，在标有序号的空白处填入一个适当的词，或填入括号中动词的适当形式。

It seems   1.    that at my age I am still fit enough to cycle  20 kilometers in an afternoon. I think my long and active life must be   2.  to the healthy life I live. I know how easy it is to start smoking and how    3.  it is to stop. During adolescence, I also became  4.  to cigarettes. When l was young, I didn't know that it could do 5.  to my heart and lungs.    6.    did I know that my cigarette smoke could affect the health of non-smokers. However, what I   7.   (do) know was that my girlfriend thought I smelt terrible and that she wouldn't go out with me again unless I stopped. 1 also noticed that I became breathless quickly. Then I knew  8. was time to quit smoking. I'm sending you some advice to help you  9.your resolve. Every time you feel like 10.(smoke), remind yourself that you are a non-smoker. Keep trying, and you will succeed.