名著导读。
某市中考体育测试有引体向上项目,在做引体向上将身体拉至最高位置的过程中,其支点作用的是( )
Yesterday ____ (is) sunny. Jim ____ (go) to the zoo with his friends. They ____ (buy) some ice cream and ____ (see) many animals. They ____ (have) a good time.
(Ⅰ)求角A的大小;
(Ⅱ)若a=1, AB→•AC→=3 ,求b+c的值.