题目

Holding doors open for people behind you, picking up litter, thanking people… these acts of kindness seem very small. 【1】 students at James Middle School know that such small acts make the world a 【2】 (good) place.Eighth-graders from James Middle School, took part in the Random(随意的) Acts of Kindness Week from March 31 to April 4. 【3】 the week, they tried their best to do kind things for others. Celeste Murray, an English teacher at the school, started the activity. Since she was little, she has always tried to do small acts of kindness in her daily life. I believe the world 如图，在△ABC中，AB＜AC，AD为△ABC的角平分线，P为AD上任意一点，求证：AC－AB＞PC－PB．