题目

为区别NaOH和Na2CO3两种无色溶液，某同学设计了以下两种实验方案： 方案1：分别取少许两种溶液，各滴入几滴无色酚酞试液，根据酚酞试液是否变红色判断各是哪种溶液？ 方案2：分别取少许两种溶液，各加入少量澄清石灰水，根据是否有白色沉淀生成判断各是哪种溶液？ (1)该同学设计的两个方案有一个是正确的，该方案是            ；另一个方案是不正确的，原因是            。 (2)请你再设计一个实验，区别上述两种溶液： 实验操作(C) Enough “meaningless drivel”. That’s the message from a group of members of the UK government who have been examining how social media firms like LinkedIn gather and use social media data. The House of Commons Science and Technology Committee’s report, released last week, has blamed firms for making people sign up to long incomprehensible legal contracts and calls for an international standard or kitemark (认证标记) to identify sites that have clear terms and conditions. “The term and conditions statement that we all carelessly agree to is meaningless drivel to anyone,” says Andrew Miller, the chair of the committee. Instead, he says, firms should provide a plain-English version of their terms. The simplified version would be checked by a third party and awarded a kitemark if it is an accurate reflection of the original. It is not yet clear who would administer the scheme, but the UK government is looking at introducing it on a voluntary basis. “we need to think through how we make that work in practice,” says Miller. Would we pay any more attention to a kitemark? “I think if you went and did the survey, people would like to think they would,” says Nigel Shadbolt at the University of Southampton, UK, who studies open data. “We do know people worry a lot about the inappropriate use of their information.” But what would happen in practice is another matter, he says. Other organisations such as banks ask customers to sign long contracts they may not read or understand, but Miller believes social media requires special attention because it is so new. “We still don’t know how significant the long-term impact is going to be of unwise things that kids put on social media that come back and bite them in 20 years’ time,” he says.Shadbolt, who gave evidence to the committee, says the problem is that we don’t know how companies will use our data because their business models and uses of data are still evolving. Large collections of personal information have become valuable only recently, he says. The shock and anger when a social media firm does something with data that people don’t expect, even if users have apparently permission, show that the current situation isn’t working. If properly administered, a kitemark on terms and conditions could help people know what exactly they are signing up to. Although they would still have to actually read them.1. What does the phrase “ meaningless drivel” in paragraphs 1 and 3 refer to?A. Legal contracts that social media firms make people sign up to.B. Warnings from the UK government against unsafe websites.C. Guidelines on how to use social media websites properly.D. Insignificant data collected by social media firms.2.It can be inferred from the passage that Nigel Shadbolt doubts whether _______.A. social media firms would conduct a survey on the kitemark schemeB. people would pay as much attention to a kitemark as they thinkC. a kitemark scheme would be workable on a nationwide scaleD. the kitemark would help companies develop their business models3. Andrew Miller thinks social media needs more attention than banks mainly because _______.A. their users consist largely of kids under 20 years oldB. the language in their contracts is usually harder to understandC. the information they collected could become more valuable in futureD. it remains unknown how users’ data will be taken advantage of4.The writer advises users of social media to _______.A. think carefully before posting anything onto such websitesB. read the terms and conditions even if there is a kitemarkC. take no further action if they can find a kitemarkD. avoid providing too much personal information5. Which of the following is the best title of the passage?A. Say no to social media?B. New security rules in operation?C. Accept without reading?D. Administration matters!