People who smoke could lose around one third of their everyday memory, researchers say. A study by a team at the University of Northumbria has shown that smokers lose more of their memory when compa
太平天国运动失败的根本原因是A ．农民阶级的局限性B ．拜上帝教不符合中国国情C ．在军事策略上的失败D ．中外反动势力联合镇压
________ many developing countries, China is in great need of science and technology. A．As B．As
阅读下面这两首诗，然后回答问题。（6分） 上邪 汉乐府民歌 上邪！我欲与君相知，长命无绝衰。 山无陵，江水为竭，冬雷震震，夏雨雪，天地合，乃
昨天的会上问了很多问题。Many questions at yesterday’s meeting.
---Shall I go to the party tomorrow? ---I would rather _____. A. come B. should come C. would come D. came
用NA表示阿伏德罗常数，下列叙述正确的是 A．标准状况下，22.4LH2O含有的分子数为1 NA B．常温常压下,1.06g Na2CO3含有的Na+离子数为0.02 NA C．通常状况下，1
图1中的变压器为理想变压器，原线圈的匝数n1与副线圈的匝数n2之比为10 : 1。变压器的原线圈接如图2所示的正弦式电流，两个20Ω的定值电阻串联接在副
，
，
，则
等于（ ）
B．
D．
，则
，∴
，∴
．故选B．