随着互联网与电子商务技术的快速发展，网购已经成为人们日常生活的一个重要部分。“网络团购”是一种新的消费模式。职业团购网站通过与商家合
He sent the headmaster an E-mail, _______ to get further information. A. hoped B. hoping C. to hope D. Hope
________ number of wild animals has been on ________ increase since the new law came into effect. A．A；不填
Dear Alan, Guess what? I have a chance to choose my new place to live in! I’m excited and a little nervous. Could you please give me some help? I’m not sure whether I will live in a
--It’s really nice of you to help me! --_________ A. My pleasure. B. Don’t say that. C. Is that so?
已知方程组 的解也是方程3x－2y = 0的解，则k = .
右图是初中化学中关于甲、乙、丙、丁四种常见物质间的转化关系图。下列说法不正确的是A．若甲为单质，丙为单质，则该反应不一定是置换反应B．若
.已知反应：2NO2（红棕色）N2O4（无色）△H＜0。将一定量的NO2充入注射器中并密封，改变活塞位置的过程中，气体透光率随时间的变化如图所示（气体颜
，集合
，则
等于 
B．
C．
D．
