题目

某学生要配制一定溶质质量分数的NaOH溶液，实验操作如图所示，其中正确的是(  ) A．取用NaOH固体 B．称量NaOH固体 C．量取一定体积的水 D．溶解NaOH固体 答案：D 【详解】 A、取用药品时瓶塞要倒放在桌面上，故A错误； B、用托盘天平称量易潮解、具有腐蚀性药品的时候要把药品放在玻璃器皿内进行，故B错误； C、用量筒量取液体读数时，视线要与液体凹液面的最低处保持 水平，故C错误； D、为了加快溶解可用玻璃棒搅拌，故D正确。 故选D。阅读与回答问题。注意：认真阅读短文，按规定词数答题。Have ever heard of Dagang Talks about News in Nanjing news channel? Do you often watch it? Here are several pieces of news he reported yesterday.News Item 1Have you ever thought of flying around the world in a new hours though the journey is as long as about 40,000 kilometres? One day maybe you can．Last Sunday, the American X-43A airplane made its first flight．It reached a speed a speed of 8,000 kilometres an hour．It became the fastest plane in the world．The X-43A is only three to four metres long, but it’s very heavy．It weighs 1,270 kilogrammes.News Item 2Have you ever got angry at books that are full of mistakes?don’t worry．It will get better soon．Last week, China started checking textbooks, dictionaried and children’s books all over the country．The government said the results of the checking would come out at the end of June.News Item 3Floods across Coahuila, the state of northern Mexico, killed at least 32 people and left 100 more missing．It was reported on Monday that the heavy rain hit the state and lasted for the whole night last Friday．Much of the river bank was broken, so about 3,000 families along the river were seriously affected.1.How many pieces of news did Dagang report yesterday? (no more than 4 words)2.Which item reported the fastest plane in the world? (no more than 4 words)3.How long will the X-43 take to finish the trip if it flies around the world?4.When will the results of the checking books’ mistakes come out?5.Why were families along the river seriously affected?