第二次世界大战欧洲策源地形成的标志是

    New Year's Day is coming. The students in Class 8 are preparing for a New Year's party. Cindy and Mary are malting red paper birds They want to put them outside (在……外面) the classroom  Lily and Alice are cleaning the desks and chairs They want a clean classroom. There are some pictures on the walls and there are also some beautiful flowers on the desks. Some boy students are learning taijiquan in the playground. They want to show (展示) it at the party. Where are Jack and Nancy? Oh, they are still in the shop. They are buying some food and drinks for the party. "We are very happy because we can have a big party," says Mike, the monitor (班长).

已知反比例函数y=﹣$\frac{2}{x}$，下列结论不正确的是（　　）

 如图是A、B两种物质的溶解度曲线，请回答：

（1）在40℃时A、B的溶解度大小关系是　____ ；

（2）a点是A、B两条曲线的交点，其含义是____ ；

（3）20℃时将20gA固体放入50g水中，充分溶解后，所得溶液的质量是____ g；

（4）若A中含有少量的B杂质，提纯A的方法是____结晶．

读我国南北方地区耕地、水资源和人口对比图，判断下列叙述正确的是（　　）