【简答题】What is color? Why do some of the things around us look red, some green, others blue? Colors are really made by reflected(反射)light(光). We see color because most of the things reflect light. Something ...
【单选题】—Do you know the colors of the Olympic rings? —Yes. They're blue, yellow, black, green and red. You can find ____ one of these colors in the flags of every country. [ ]