题目

化学是一门以实验为基础的科学．下列有关实验问题的说法中正确的是（ ） A．在做“粗盐中难溶性杂质的去除”实验时，一定要用到过滤操作B．碳酸盐、碳酸氢盐中只有碳酸盐能与盐酸反应产生CO2C．沉淀过程中一定伴随着化学变化D．能使无色酚酞溶液变红的物质一定是碱 答案：考点：氯化钠与粗盐提纯；酸碱指示剂及其性质；盐的化学性质；化学变化的基本特征．. 专题：物质的变化与性质；常见的碱 碱的通性；常见的盐 化学肥料． 分析：A、根据粗盐提纯的步骤，进行分析判断． B、根据碳酸盐、碳酸氢盐均能与酸反应，进行分析判断． C、沉淀过程中不一定有新物质生Swim Birthday PartiesAges 3 and up.Pool parties are during recreation swim in the 25-yard pool. Each party consists of an hour of celebration in a private room. Parties are for 1—5 children. All non-swimmers or children requiring floatation must be at arm’s length from the pool and accompanied by an adult or guardian.Please contact Sarah Hagan 762—8384x210.Fee: Members $ 175/Non-members $225Youth Fitness Birthday PartiesLeave the party activities to us! Your party package includes:1/2 hour set-up,1 hour program time including equipment,props,etc.1 hour party time for cake,presents,etc.,1/2 hour clean-up time and 1 or 2 hours specialists. Parents supply decorations, food and paper goods. To schedule a Youth Fitness Birthday Party, call Mary Ann Genuario (x282).Fee: $295 for up to 10 children,$10 each additional child—16 children maximum. Non-member price available upon request.The Art Spot Birthday PartiesThe Art Spot offers a variety of creative fine art parties for Ages 4—Adult! We supply the invitations, a balloon bouquet(花束), paper goods, project materials and a party host; all you need to bring is the cake!Parties are one and a half hours, the first hour the group create their art project, and last 1/2 hour is for cake and presents! Parties are usually held on Friday nights and weekends but weekday parties are available.Cost: $21 per child.Rain or shine there’s no better place than the Art Spot for your child’s next party!Nursery School Birthday PartiesIf planning a party is not your thing, let us do the work for you! We offer a variety of pre-planned parties to choose from. You may also do a combination of 2 parties for boy/ girl parties. All parties are on Saturday afternoons between the hours of 12:00 p.m. and 4:00 p.m. and are one and a half hours in length. Parties include a craft or activity and paper goods. You may arrive 15 minutes prior to your scheduled time to set-up. To schedule a party please contact Kim Murphy(x214).Fee(Up to 15 children):$200 Members/ $250 Non-member,$15 each additional child.1.The phrase “be at arm’s length” probably means“______________”.A. be as careful as possible B. be as long as an armC. be as near as possible D. be as faraway as possible2.If 12 children take part in Youth Fitness Birthday Parties, they will pay ____________.A.$ 455 B.$315C.$ 200 D.$2503.If your child joins in the Art Spot Birthday Parties, he will .A. swim in the 25-yard poolB. spend half an hour to clean upC. create his own art projectD. do activities with other kids4.What information can you get from the passage?A. You can schedule the party when it is convenient for you.B. The number of people for these parties is limited.C. You need to bring nothing to join in the birthday parties.D. All of these birthday parties center on a special theme.