题目

_________shortly after it stopped raining. A . There appeared a colorful rainbow in the sky B . In the sky did a colorful rainbow appear C . There a colorful rainbow appeared in the sky D . There in the sky a colorful rainbow appeared 答案：A有一长方体游泳池，长80米，宽50米，深2米．请根据这些信息解决下面问题：①这个游泳池占地面积是多少平方米？②这个游泳池的底面  和四周 贴白色的瓷砖，瓷砖的面积是多少平方米？③游泳池每日凌晨换水，现在水深1.4米，用每分钟排水40立方米的水泵向外排水，需几小时排完？