traditional lighting is less durable and dearer B.a laser excited the quantum dots C.America adopted LEDS D.graduate students work hard E.quantum dot mixtures are magic F.it is more efficient Unlike traditional lighting, LEDs do not give out heat so ______.
A.
【参考答案】
F F 解析：题干涉及的内容在第五段可以找到，有关的句子是：“LEDs don't emit heat．so t......