先化简，再求值：（ $\frac{a^2-4}{a^2-4a+4}$ ﹣ $\frac{1}{2-a}$ ）÷ $\frac{2}{a^2-2a}$ ，其中a是方程x²+3x+2=0的根．

Jerry does morning exercise every day.(改一般疑问句）
____ Jerry____  morning exercise every day?
The water was too dirty for us to drink.(改为同义词)
The water was ____dirty ____ we couldn't drink it.
I don't know David’s e-mail address.
He doesn't know David's e-mail address, either.(合并一句话)
____he____  I know David's e-mail address.
The author will leave for Xingyi in a month.(对划线线部分提问)
____will the author leave for Xingyi?
I think Allen must be playing basketball with his brother on the playground,
____ ？(写出其反意疑问部分）

人体呼出的气体中二氧化碳量增多，增多的二氧化碳产生于（  ）