急性卡他性结膜炎，俗称“红眼病”，是由结膜炎致病细菌感染引起的一种常见的急性流行性眼病．春夏之交，天气转暖，细菌生长繁殖快，容易造成“红眼病”大流行．请据资料回答：
A. I can't find my book.
B. Read the newspapers to old people.
C. Over there.
D. Because we can reuse them.
E. Yes.
（2015•温州）分解因式：a2﹣2a+1=____．
