题干

小华探究杠杆平衡条件时,使用的每个钩码的质量均为50g,杠杆上相等刻线的距离相等,小华将杠杆调节水平平衡后,在杠杆上的B点悬挂了3个钩码,如图所示.为使杠杆保持水平平衡状态,应该在A点悬挂____个钩码.

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同类题4

                                                                                  Sea Life Melbourne Aquarium (水族馆)

   The all-new Sea Life Melbourne Aquarium, situated in the heart of Melbourne’s CBD, is one of Victoria’s leading visitor attractions and an unforgettable outing for the whole family. Having 12 amazing zones of discovery, Sea Life Melbourne Aquarium is the very place that you cannot miss when you visit the city.

* Opening Times

     Sea Life Melbourne Aquarium is open from 9:30 am until 6:00 pm every day of the year, including public holidays. Last admission is at 5:00 pm, one hour before closing.

* Location ( 位置)

     Sea Life Melbourne Aquarium is located on the corner of Flinders Street and King Street, Melbourne. It is siyuated on the Yarra River, opposite Crown Entertainment Complex.

* Getting to Sea Life Melbourne Aquarium

     Train

     The Sea Life Melbourne Aquarium train stop is located on the free City Circle Tram route (公交线路) and also routes 70 and 75. City Circle trams run every 10 minutes in both directions.

     Shuttle Bus

     The Sea Life Melbourne Aquarium is a free bus service, stopping at key tourist attractions in and around the City. Running daily, every 15 minutes from 10:00 am to 4:00 pm.

      Car Parking

      While there is no public car parking at Sea Life Melbourne Aquarium, there are several public car parking lots available only a short walk away.

* Wheelchair Access

      Sea Life Melbourne Aquarium provides people in wheelchairs with full access to all 12 zones. Each floor also has wheelchair accessible toilets.

* Terms

      Tickets will be emailed to you immediately after purchase or you can download and print your ticket once payment has been accepted. Please print out all tickets purchased and present at the front entrance of Sea Life Melbourne Aquarium. No ticket, no entry!


同类题5

阅读下文,回答相关问题。
        去除饮水中可能致命的细菌或许会成为纳米管最早的实际用途之一。
        科研人员已经研制出能让细菌聚结成块的纳米管,随后就可以将菌块从水中滤出,并消灭它们。他们进行的实验很容易用于实践。
        南加州克来姆森大学负责此项研究的孙亚平说,这种纳米管最初或可以用作水净化处理厂的过滤器。他的研究成果发表在最新一期的《化学通讯》杂志上。
        新研制的纳米管能捕捉大肠杆菌O157:H7,即臭名昭著的“汉堡细菌”,被它污染的肉可能置食客于死地。他给纳米管表面覆上一层半乳糖分子,而半乳糖分子能与大肠杆菌表面的受体蛋白粘合。每根纳米管都覆有数以百计的半乳糖分子,因此能一举拿下大量细菌。
        该研究小组还研制了能捕捉污染事物的另一种常见细菌――空肠弯曲杆菌――的纳米管。这种细菌多见于肌肉之中。这一次纳米管的表面富有甘露糖分子,它能与空肠弯曲杆菌表面的受体蛋白粘合。孙说:“我们正在研制富有能捕捉不同细菌的多种配位体‘糖’的纳米管。这是可行的。”
        研究者认为,从理论上说,这种纳米管可以用于将细菌从患者的血液中滤出,不过它们必须首先经过试验,排除任何毒副作用的可能。英国史密斯叔侄公司的彼得·阿诺得说:“将来,类似于这类碳纳米管的交互性生物材料有望选择性地捕捉和消灭致病细菌。”该公司是一家医疗技术公司,正在研制能加快组织修复的生物材料。
        研制临床诊断用的纳米材料的英国奥克斯尼卡公司的凯文·马修斯说,孙的工作是传统无机化学与生物化学相结合的极好例子,二者结合“提供的可能性超越了其中任何一种单独所能提供的可能性。”

                                                                                                                                                            摘自2005年3月12日《参考消息》
       注:“半乳糖”和“甘露糖”是配位体糖的两个具体种类。