(09年西城区抽样)“,且”是“”的( )A. 充分不必要条件 B. 必要不充分条件 C. 充要条件
We should make a s of the results of the exam briefly and report to the headmaster.
如图4-2-8所示,是法拉第在1831年9月24日所做的一次实验装置。他把两根磁棒搭成倒V字形,中间加入一个套有线圈的软铁棒,线圈两端与电流计相连。当
岩浆的主要发源地是( ) A.地壳 B.地幔 C.地核 D.岩石圈
Steven has a lot of work to _______ in the office since he has been away for quite a few days. A. take up B. make up C. work out D. carry out
某高科技公司根据市场需求,计划生产A、B两种型号的医疗器械,其部分信息如下: 信息一:A、B两种型号的医疔器械共生产80台. 信息二:该公司
Tom: Sandy. It seems that only half of the students passed the final exam. Sandy: Really? The exam 44.have been very difficult this time. Tom: Well, I’m really 45.(surprise) too. There ar
一种商品价格(P)上涨,会引起其替代商品(Q1)需求量的变化,同时也会引起其互补商品(Q2)需求量的变化。下列曲线图中正确反映它们之间的变动