下列物质能发生消去反应的是( ) A．CH3Br B． C． D．
下列物质结构图中，大黑点代表原子序数从1到10的元素的原子实(原子实是原子除去最外层电子后的剩余部分)，小黑点代表未用于形成共价键的最外层电
The wounded soldier died _____I had a chance to know his name and family. A. after B. while C. until D. before
Are you able to send a letter with pictures and sounds to someone, anywhere in the world without putting a stamp on it? With an e-mail you can just do that. Using computers you can send e-mails quickl
为了解自己的身体情况，健康的小明做了一些测量，其中记录错误的是：（ ） A．质量50kg B．身高160m C．
句形转换：1. It is my first time to be in a plane, so I don’t know what I should do.（写出同义句子）It is my first time to travel ________ plane, so I don’t know what _________.2. “
如图， AB ⊥BC ， ∠ABD 的度数比 ∠DBC 的度数的两倍少 30°，设 ∠ ABD 和 ∠DBC 的度数分别为°、°，那么下面可以求出这两个角的度数的方程组是（
杭州市2008年元旦的最高气温为8℃，最低气温为－2℃，那么这天的最高气温比最低气温高 （ ）A、-10℃ B、-6℃ C、6℃
