The world is divided into two parts. One half of the world is rich and 1is poor. In the poor part, a lot of people have2got enough to eat. When they are ill, none of the3can receive them because they have no money. In the rich 4, people eat very well, 5 a dog or a cat in North America eats   6than a child in poorer countries.
   The poor countries have some difficult problems. Sometimes the land is too poor to grow7on. People there have 8rich land nor enough water. The land9be made better, but a lot of things must be done. The people must be taught and water must10.
   But rich countries have problems, too. There are not always good places to 11. Sometimes the air is not clean and the rivers are too 12to swim in or to drink. The roads and streets are full of people and cars. Cars and buses have to move 13. Noise is too much. Some people have no houses to live in. Something must be done about these problems. The air and the rivers must be cleaned and be 14clean. More houses have to be built. 15these things cannot be done easily.

某生物兴趣小组的同学为研究植物的生命活动，设计了A、B、C三个实验装置，实验在夏天某一晴朗的上午进行．请据图分析回答：

____＋15=30

____＋25=50

____＋35=70

____＋45=90

企业是市场经济的主体。在供给侧结构性改革背景下，党和政府高度重视帮助企业降低成本。

材料一：2015年全国企业负担总指数为0．853，较上年略有提升。79%的企业反映“人工成本快速攀升”，66%的企业反映“融资成本高”，54%的企业反映“生产要素价格上涨”，52%的企业反映“税费负担重”，68%的企业希望取消不必要的行政审批，51%的企业希望取消不合规收费。

材料二：今年中央经济会议强调，开展降低实体经济成本行动，降低制度性交易成本，转变政府职能、简政放权。《中共中央关于制定国民经济和社会发展第十三个五年规划的建设》指出，限制政府对企业经营决策的干预，减少行政审批事项，省级政府推行权力清单制度并向社会公布，减少和简化审批流程，降低企业的经济、时间和机会等成本。