E
City officials are hoping to use the power of dog droppings. San Franciscans already recycle more than 60% of their dogs’ droppings, but in this dog-friendly town, such wastes make up nearly 4% of residential waste, or 6,500 tons a year.
Within the next few months, Norcal Waste, a company that collects San Francisco’s wastes, will begin a trial program under which it uses biodegradable (生物分解的) bags and dog-waste carts to pick up droppings at a popular dog park.
The droppings will be thrown into a machine called a methane digester (沼气处理机), which is basically a tank in which bacteria feed on droppings for weeks to create methane gas.
The methane could then be piped directly to a gas stove, a steam heater, an air turbine or anything else powered by natural gas. It can also be used to produce electricity.
Someone doubts whether this plan is practical. But Norcal Waste spokesman, Robert Reed points to San Francisco’s creative food composting (混合肥料) program, which began 10 years ago. It is a proof that an unusual idea can work in this forward-thinking city. Norcal Waste collects 300 tons of food left over after meals per day from homes and restaurants and changes it into a rich fertilizer sold to grape farms and organic farms.
Methane digesters are nothing new. The technology was introduced in Europe about 20 years ago, and more than 600 farm-based digesters are in operation there. Nine are in use on California cow farms, and chicken and pig farms elsewhere in the United States also use them.
“The main obstacle is probably getting communities around the country the courage to collect dog droppings, to give value to something we’d rather not talk about,” Brinton, a recycling and composting consultant, said. “San Francisco is probably the king of pet cities. This could be an advantage of it, which is very important.”
Some other experts believe energy production from dog droppings must become more attractive economically before it gets popular. Landfill space is relatively cheap, and natural gas and electricity also remain fairly inexpensive. However, Reed said confidently, “Now, the city authorities asked us to look at dog waste specifically.”
61. How many dogs’ droppings can be recycled at present per year in San Francisco?
A. About 6,500 tons. B. About 169,000 tons.
C. About 260 tons. D. About 3,900 tons.
62. It can be inferred from the passage that .
A. there are many pets that are treated well in San Francisco
B. Norcal Waste is a company of refuse (垃圾) treatment, which collects dog wastes only
C. most of the farms in Europe use Methane digesters
D. Brinton doesn’t feel optimistic about the collection of dog droppings in San Francisco
63. The underlined word “obstacle” in Paragraph 7 most probably means .
A. interest B. effect C. difficulty D. purpose
64. Which of the following is TRUE according to the passage?
A. San Francisco is a city full of innovation.
B. Dog droppings can be changed into methane gas in several days.
C. It is the first time to utilize animal waste in San Francisco.
D. Utilizing dog droppings presently is more economical than the landfill.
65. Which of the following can be the best title of this passage?
A. Animal wastes collection by Norcal Waste
B. Changing dog droppings into energy
C. Methane digester technology in San Francisco
D. A dog droppings composting program
