题目

一个小球在水平面上做匀速直线运动,经5s前进1.2m,来到一个下坡路做匀加速直线运动,坡长3m,小球经过4s到达坡底.求小球在斜坡上的加速度及到达坡底时的速度. 答案：13. a=0.255m/s2;  v=1.26m/s;阅读理解。      The Canadians love the great outdoor-20% of the Canadians go camping each year-and consider the natural phenomena of their country to be unequalled in the world. More than 90% of Canada remainsundeveloped, and the Canadians are quite content to keep it that way.      With no lack of land, their cities tend to grow horizontally (水平地) rather than vertically (垂直地). Just about every house in town has a large grassy lawn that requires mowing in summer and at least fourtrees: two at the front and two at the back.     In a country with that much natural space, it seems logical that one would want to look after it. Not allthe Canadians have seen the Rockies, but every single one of them wants them to be well cared for and notburied by commercial development or tourist litter by the time they get there.     To solve trash problems, several cities are using technology to transform household waste into soil-enriching compost (堆肥). Edmonton has constructed North America's biggest composter. Citizens place recyclable materials into blue bags which are picked up and taken to a sorting and treatment facility. The $100-million plant, which covers an area the size of four football fields, processes over 1 000 tons of refuse a day, enabling Edmonton to reuse 70% of its residential waste. Everything from glass and milk cartons (纸盒) to metals, plastic, even concrete and asphalt (天然沥青) from sidewalk repairs are recycled.      Another leader in recycling is the coastal city of Halifax where the recycling program has made its wayinto law, making it illegal to throw an apple core into a garbage can. 1. What makes the Canadians satisfied according to the passage? [     ]A. That most of their country remains wilderness.B. That there is little grassy land and few trees.C. That they can go hiking every year.  D. That all of the rubbish can be dealt with. 2. How many tons of the household waste in Edmonton can not be processed in North America's biggest     composter a day? [     ]A. over 700 tonsB. over 1000 tonsC. over 1428 tons D. over 428 tons 3. All of the following statements are right Except _____. [     ]A. It is logical that the majority of Canadians want to look after their natural spaceB. In Halifax, throwing an apple core into a garbage can'is against the lawC. Not all the Canadians have ever visited the-Rockies and want them to be well cared forD. The $100 million plant can recycle most of the household waste in Edmonton