下列关于光的现象的说法中正确的是  （      ）

全国人大常委会办公厅2011年4月25日在中国人大网站全文公布了《中华人民共和国个人所得税法修正案（草案）》，向社会广泛征求意见。截止五月初，已经有提交确认的意见接近19万条。这是公民通过

下列属于非可再生资源的是（  ）

请认真阅读下列短文，从短文后各题所给的A、B、C、D四个选项中，选出最佳选项。
A
    If you travel by air across the center of Africa or South America, you fly over forests for thousands of kilometers. These great forests are the oceans of trees. There are full of thousands and thousands of different kinds of plants and animals.
    However, the world's forests are getting smaller all the time. We are cutting down the trees because we need wood, and we need more farm land. Some people say that there will not be any forests like these in 20 or 30 years. what will happen if they disappear?
    If we cut down our forests, a lot of plants and animals will disappear from the world. In a lot of places the new farm land will soon look like the old deserts. Crops will not grow there. It will not rain very often, and the weather will get very hot. Perhaps the climate of the world will change. This will be dangerous for everyone in the world. That is why we must take care of our forests.

如图所示是某一基本触发器的逻辑图，请完成下列各题，在“       ”处填写上相应内容。