题目

若<<0，则下列四个结论①|a|>|b|；②a＋b<ab；③＋>2；④<2a－b. 其中正确的是. 答案：∵<<0，∴b<a<0， ∴－b>－a>0， ∴|b|>|a|，故①错误. ∵b<a<0，显然②正确. 又∵>0，>0，且≠，∴③正确. 又∵－(2a－b)＝－2a＋b＝ ＝<0， ∴<2a－b，∴④正确. 答案：②③④Join the Camp Jane is my good friend. She is thirteen yearsold. She is kind to (对 好）children. She wantsto find a summer job. One day she hears that City Kids Summer Camp needs help with sports, music and computers. Jane is very glad (高兴）to hear this.Jane likes sports very much. She can play basketball and volleyball. She can swim, too. As for music, she is good at playing the violin, the piano and the guitar. She can also sing lots of popular songs. Jane often does her homework on the computer. She uses the computer to send (发送）e-mails to her pen friends. But she never (从不）plays games on the computer. This is Jane’s e-mail ad-dress：jane!997 @ hotmail. com. If you want to be Jane’s pen friend, you can write to her. You can also call her. Her telephone number is 880-59832.Now, dear friends, can Jane join the Summer Camp? Please help her fill in the form (填写表格)below.Form for the City Kids Summer CampNameJaneAge26.E-mail address27.Sports abilities (能力）28.Music abilities29.Computer abilitiesDo homework on the computer, send e-mailsTelephone number30.