）从苯酚的乙醇溶液中回收苯酚有以下8种可供选择的操作，其中合理的操作是（　　）

①蒸馏　②过滤　③静置分液　④加入足量金属钠　⑤通过足量CO₂　⑥加入足量NaOH溶液　⑦加入乙酸与浓硫酸混合液加热　⑧加入足量的三氯化铁溶液．

魏巍的报告文学《谁是最可爱的人》，1951年4月11日在《人民日报》刊登，影响了几代中国人，书中对于中国人民志愿军的故事应该取材于下列哪一时期（    ）

大于﹣3而不大于3的所有整数的和是（　　）

生物的多样性不包括（　　）

    Today is Monday. It is sunny today. There is a sports meeting in our school. There are many students and players on the playground. Some basketball players are playing over there, and their classmates are watching. Some girls are running. There is a big tree on the playground. Some boys are jumping under the tree.