题目

Keeping a busy social life among lots of friends may keep people thinner than spending several hours in a gym, according to scientists. Scientists believe social activities can release a brain chemical that changes white fat into brown fat. Brown fat burns calories (卡路里). To produce heat, while white fat keeps calories and make us fatter.Changing white fat into brown fat is very difficult, generally requiring long-term exposure to cold conditions or making part of the body’s nervous (神经的) system active. However, scientists from Ohio State University think that having a busy socia下列新中国成立后的重大历史事件，按时间先后顺序排列正确的是①三大改造完成 ②第一届全国人民代表大会召开③西藏和平解放 ④十一届三中全会召开A.④①②③B.②④①③C.①②④③D.③②①④