下面光学仪器中，能成放大实像的是（　　）

  ① ② （0＜x＜π）     ③y=e^x+4e^﹣x④y=log₃x+4log_x3．

2016年12月，全国人大常委会审议通过了《环境保护税法》，我国的环境治理由“排污费制度”转变为“环保税制度”。这一转变的意义在于（   ）

将文具盒放在水平桌面上的物理课本上，下列几种说法中正确的是（   ）

     What is color? Why do some of the things around us look red, some green, others blue?
    Colors are really made by deflected (反射) light. We see color because most of the things reflect light. In the same way, if something is green, it reflects most of the green light. If something reflects all light, it is white. If it doesn't reflect any light, it is black.
Some of the light is reflected and some is taken in (吸引) and turned into (变成) heat (热能).The darker the color is, the less light is reflected, the more light is taken in. So dark-colored clothes are warmer in the sun than light-colored clothes.