已知函数. (1)若a,b都是从0,1,2,3,4五个数中任取的一个数,求方程f(x)=0的概率. (2)若a,b都是从区间[0,4]任取的一个数,求f(1)>0成立时的概率. 答案:解:(1)a,b都从0,1,2,3,4五个数中任取的一个数的基本事件总数为N=5×5=25个. 方程f(x)=0有根的条件为因为事件“”包含所以事件“”的概率为;…………6分 (2)a,b都是从区间任取的一个数,所以事件“”的概率为…………12分 用括号中所给词的适当形式填空。 1.He _____________(go)to work by bus every day. 2.There are lots of things_____________ (do)today. 3.Many children like_____________(watch)cartoons(卡通片). 4.Mr. Green _________________(marry)ten years ago and had three children. 5.It was very difficult____________ (build)such a railroad at that time