You can be proud of yourselves, even if you can only make one or two of these green changes. The goal here is to limit carbon dioxide and other greenhouse gases, which are closely associated to the big problem of global-warming. Strategy 1: Bring your own cup to Starbucks You’ll get a 10 cent discount, and it’s one less paper cup to end up in a landfill. While you’re there, pick up some free bags of spent coffee grounds to use as ‘‘green’’ fertilizer in your garden. The payoff: The store won’t create more waste when they throw away a cup. Strategy2: Turn off your computer When in standby mode, your PC is still using energy. In fact, 75percent of electricity used in your home comes from electronics that are turned off. The payoff: Turning off a monitor for 40 hours a week may only save $5 a month, but it reduces CO2 by 750 pounds Strategy 3: Reuse plastic bags Instead of throwing away 100 billion plastic bags a year, try and get a second, third, or tenth use out of them. Better yet, next time you shop, try a reusable bag. The payoff: You’re reducing pollution. The amount of oil it would take to make just 14 plastic bags would run your car for one mile. Strategy4: Use recycled paper in the bathroom Most of the toilet paper we use is made from trees found in forests previously untouched by humans. The payoff: If every household replaced one roll of toilet paper with a recycled one, 424000 trees would still be standing. Look for eco-paper towels too. Strategy5: Buy energy-efficient appliances（电器） Replace the old fridge with an Energy Star appliance and you’ll use 15 percent less energy. It might be a little expensive to buy, but you’ll save money on your electricity bills and help the environment. The payoff: If we all used one Energy Star appliance at home, it would be like planting 1. 7 million acres of new trees. Strategy 6: Plant a tree Adding green to your garden is beautiful and earth-pleasing. The payoff: Just one tree will help make cleaner air and save the environment from 5000 pounds of hot carbon dioxide each year. 54. What is the best title for the passage? A. Ways to save money at home B. Ways to be earth-friendly C. Ways to end global-warming D. Ways to limit carbon dioxide 55. What benefits do these strategies have in common? A. They all help reduce the use of energy like electricity. B. They all cut down the amount of the paper. C. They all result in producing less greenhouse gases. D. They all help to preserve our trees and forest. 56．Which strategies suggest recycling or reuse of things? A．Strategies 1&3    B．Strategies 2&5 C．Strategies 3&6    D．Strategies 4&5.