题干

如图所示是简化的多用电表的电路.转换开关S与不同接点连接,就组成不同的电表,已知R3<R4,下面是几位同学对这一问题的议论,请你判断他们中的正确说法是(  )

A:S与1、2连接时,多用电表就成了电流表,接1量程比接2量程大

B:S与3、4连接时,多用电表就成了电流表

C:S与3、4连接时,多用电表就成了电压表

D:S与5连接时,多用电表就成了欧姆表

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A,C,D

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    Paying a higher price than usual for a ticket to see a film in 3D is the annoyance of many a cinema-goer's life.

    But there may be a benefit to doing so, as a study has found that 3D films exercise the brain and improve short-term functioning in a similar way to brain-training tests.

    The research found that people who watched a movie in 3D improved cognitive (认知) skills, compared to those who watched it in 2D.

    The research was led by neuroscientist(神经学家) Dr Patrick Fagan from Goldsmiths University in London. More than 100 people took part in the experiment, where participants watched Disney film Big Hero 6 in either standard format or RealD 3D.

    They also carried out a brain-training-style test before and after seeing a section from the film. The test covered memory, reaction times and cognitive function and the results were compared later.

    According to the research, which was carried out in partnership with science group Thrill Laboratory, participants experienced a 23 percent increase in cognitive processing, as well as an 11 percent increase in reaction times.

    Dr Fagan said that the results showed enough of an improvement in brain function to suggest that 3D could play a part in improving brain power in the future.

    "These findings are more significant than you might think," he said. "It is a fact that people are living longer and there is a noticeable decline in cognitive brain function in old age which can worsen future quality of life. There has never been a better time to look at ways to improve brain function. The initial results of this study show that 3D films may potentially play a role in slowing this decline."

    A second part of the experiment involved those watching the film being fitted with headsets that scanned brain activity and this too showed heightened (加强的) activity when watching 3D. According to the results, participants were seven percent more engaged with what they were watching, adding to argument that 3D movies are more like watching real-life—something Professor Brendan Walker from Thrill Laboratory agreed with.

    "As Professor Brendan Walker's test concluded, 3D films are more attractive and heighten the senses — this, in turn, makes the brain run at quicker speeds," Dr Fagan said.