目前，美国接受一批中国、印度等国的科技人才和著名学者迁入．影响该人口迁移的主要因素是（　　）

两盆冰水混合物，各自处于太阳下和背阴处，在盆内冰尚未熔化完以前，用温度计去测盆内水的温度时（  ）

湖北省政府在《关于加快发展养老服务业的实施意见》中强调，完善城乡养老公共基础设施建设，建立健全养老服务业的税收优惠政策，大力发展社区居家养老服务网络，推动公民积极参与养老服务业的发展。湖北省政府的做法启示我们解决老龄化问题需要（    ）

①推进生态文明，创造良好生活环境②巩固基层政权，实现居民自我管理③进行宏观调控，组织国家经济建设④加强社会建设，完善基本公共服务

   People are often killed while c____  the road. Most of them are old people and c____ . Old people are often killed because they are careless. People should look and listen b____  they cross the road. A car, a truck or a bus can't stop very q____ if it is going very fast. It will travel many meters before it s____ . Pedestrian(行人)don't know this. They think that a car can stop right away. It is h____ for a pedestrian to know how fast a car is traveling. The only s____ way to cross the road is to look at b____ ways, right and left. The correct way to cross the road is t____  walk quickly when the traffic l____ turn green.