【单选题】When light illuminates an object, part of it is absorbed and part reflected the ______lightness of an object depends on the proportion of light that is reflected.
【简答题】完形填空(共20小题;每小题1.5分,满分30分) The town I live in is about to put cameras at all traffic lights to catch people who run red lights. It 1 me of how many people I’ve seen who take the yellow light as a 2 to ...