题干

经济学上有个古老的原理叫“劣币驱逐良币”,说的是在铸币时代,当那些“劣币”(低于法定重量或者成色的铸币)进入流通领域后,人们就倾向于将那些“良币”(足值货币)收藏起来。结果,市面上“良币"越来越少,“劣币”越来越多。“劣币”之所以能驱逐“良币”:主要是因为                                 (   )
①作为流通手段的货币,不一定是足值的货币
②货币在商品流通中充当商品交换媒介
③交易双方对货币的成色或者真伪不十分了解
④劣币本身也是一种商品,也具有价值

A:①③

B:②③

C:②④

D:①④

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C

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    When you see someone you know, the easiest way to recognize them is by their face—but not everyone can do this. Many people have prosopagnosia, or face blindness, which is a neurological(神经病学的)condition where the part of the brain that recognizes faces fails to develop. It can stop people recognizing partners, family members, friends or even their own reflection. It was once thought to be caused by brain injury (acquired prosopagnosia) but now a genetic link has been proved (development prosopagnosia).

    Acquired prosopagnosia is a very rare but as many as one in 50 people may have developmental prosopagnosia. There's no specific treatment, but training programmes are being developed to help improve facial recognition.

    For many, the situation can be dangerous. I've heard stories of people being robbed by strangers claiming to be family members, or of children wandering off strange men.

    It was only is this century that researchers began to realize exactly how many people in this world were quietly living with the condition.

    Like a blind person who can recognize family members by their footsteps, prosopagnosics are forced to develop unusual ways of discovering who it is they're meeting or talking to. From the obvious markers like hair and voice, to the way one sits, stands or walks, they rely on dozens of means to get through ordinary life.

    Faces are an important part of identity. Not to be recognized feels terrible—it's as if you've been overlooked, like someone's saying you don't matter. But it's nothing to the pain of knowing that you're hurting people's feelings constantly, and yet being completely unaware that you're doing it in the moment. To be alienated(隔离的)from the world of faces is a strange position to be in, but I'm comforted by the thought that articles like this will do a little to help people forgive me and others like me.