题目

阅读填空 阅读短文及文后选项，选出可以填入空白处的最佳选项，把答案写在答题卷相应的空格中．Can you imagine a world without the Internet？It's surprising to think about it.【1】This is the second highest number of users in the world after the United States.Today,66% of Chinese netizens （网民） are teenagers.They spend about thirteen hours every week online, said Qian Hulin,an Internet expert.Doctor Song in Beijing Xuanwu Hospital said about 14% of Chinese netizens are teens． 【2】．The main reasons why teenagers surf the Web are to search f已知函数． （Ⅰ）求的值； （Ⅱ）求函数在的最大值．