阅读理解4

The term “off the grid” refers to living in a self- sufficient manner without reliance on one or more public utilities. On 13 April 2006, USA Today reported that there were some 180,000 families living off-grid in America, a figure that has jumped33 percent a year for a decade. Because many third-world citizens have never had the chance to go on the grid, current estimates are that 1.7 billion people live off-grid worldwide.
Off-the-grid homes do not rely on municipal water supply, natural gas, electrical power grid or similar utility services. A true “off the grid"house is able to operate independently of all traditional public services. Electrical power can be generated on-site with renewable sources such as solar, wind orgeothermal(地热的) energy; with a generator and adequate fuel reserves; or simply done without. Such electricity system is called a stand-alone power system. On-site water sources can include a well,stream, or lake. Depending on the water source, this may include pumps and / or filtration. Rainwater can also be harvested.
In his book How to Live Off-grid, Nick Rosen lists seven reasons for going off-grid. The top two are saving money, and reducing the carbon footprint. Another is survivalism, which means preparing for emergencies such as disruptions in social or political order. Others include preparing for the collapse of the oil economy and bringing life back to the countryside.
Going off-grid can be done to lower the environmental impact of living,as the typically limited amount of on-site renewable energy available is an incentive to reduce its use. But if energy usage is not reduced, going off-grid actually has a larger environmental impact against using the grid, due to the lower efficiencies of the components. It is often done to residential buildings only occasionally occupied, such as vacation cabins,to avoid high initial costs of traditional utility connections.Other persons choose to live in houses where the cost of outside utilities is prohibitive,or of such a distance away as to be impractical.
26. What does the passage say about people living in third-world countries?
A、About 1.7 billion of them are currently living off-grid.
B、Many of them have no access to modern public utilities.
C、Their homes are getting more dependent on public utilities.
D、The number of them living off-grid is increasing by 33 percent a year.
参考答案：B
27. A house that is truly off the grid is able to operate
A、without using any on-site renewable energy
B、without using any water filtration equipment
C、without relying on traditional public utilities
D、without relying on independent power supply
28. Which of the following is NOT a reason for going off-grid given by Nick Rosen?
A、Expanding public services.
B、Reviving the countryside.
C、Reducing carbon emission.
D、Preparing for political instability.
参考答案：A
29. According to the passage, what may be a negative effect of living off-grid?
A、It may discourage people from paying for traditional utility connections.
B、It may limit the amount of on-site renewable energy available for the house.
C、It may increase the cost of residential buildings only occasionally occupied.
D、It may do harm to the environment due to lower efficiencies of energy usage.参考答案：D
30. What is the author's attitude toward "off the grid" life?
A、Positive.
B、Neutral.
C、Negative.
D、Indifferent.
参考答案：B。