单选题   There were limits to how green Bruce Letvin was willing to go. For years, the 53-year-old anatomy professor had wanted to install solar panels on his Manhattan Beach, Calif., home. But the up-front installation costs always outweighed the benefits for the environment and his conscience. This spring, however, he managed to work out green financing with the help of solar company SunPower. After determining that his electricity bills and roof exposure were large enough to make him a good candidate for its solar panels, the company helped him find a 15-year loan for the $64,500 system. Yes, his $550 loan payment is more than the $300 or so he used to spend each month on electricity bills,—so far, he has generated enough solar power that he doesn't need to take any juice from the grid—but after he pays off the loan, his power will be free.
    That stiff up-front cost has always been the biggest barrier to residential use of solar power. An average set of rooftop panels costs $20,000 to $30,000 and takes 10 to 15 years to produce enough electricity to pay for itself—a deal not unlike asking a new cell-phone owner to pay in advance for a decade's worth of minutes. But that equation will change as the cost of solar panels drops and the price of fossil-fuel-generated electricity rises. And now solar companies and banks are helping homeowners stretch the cost over the lifetime of the panels, and sunny California is at the forefront of this trend. SolarCity, one of the biggest panel installers in the state, began offering no-money-down leases for home installation. Says CEO Lyndon Rive, 'If you had the choice of using clean power over dirty power and paying less for it, wouldn't you take it?'
    Still, solar isn't for every home. Different parts of the U.S. receive vastly different amounts of sunlight, so a solar panel in sun-drenched Las Vegas will always be more productive than one in cloudy Seattle. Incentives vary from state to state and can tip the numbers as well. But financing means that at least you won't need a lot of excess green to go green.
单选题     Why didn't Bruce Letvin install solar panels at home though he has been willing to for years?
 
【正确答案】 C
【答案解析】第1段提到，安装太阳能电池板的前期费用总会超过它给环境带来的价值，也动摇了布鲁斯的决心，由此可知是前期的高额费用阻碍了布鲁斯的意愿，故答案为C。文中没有提到布鲁斯支付不起太阳能电池板，A是对原文的错误理解，故排除。文中提到“太阳电力”公司调查布鲁斯家的结果说明他家符合安装太阳能电池板的条件，故B错误。文中没有提到前期费用超出了它将来的好处，故D错误。
单选题     What is said about Bruce Letvin's solar panels?
 
【正确答案】 B
【答案解析】第1段提到，布鲁斯获得了一笔15年的贷款，也就是说，他要在15年内付清太阳能电池板的费用，故答案为B。原文说的是“太阳电力”公司帮布鲁斯教授获得了一笔贷款，不是免费提供给他太阳能电池板，故A错误。第1段提到，现在他每月支付550美金的贷款，但是太阳能电池板产生的电量已经足够他使用，也就是说他现在不需要支付电费了，故C错误。D在文中并未提到，故可排除。
单选题     What do Lyndon Rive's words imply?
 
【正确答案】 C
【答案解析】第2段最后一句提到，“太阳能城市”的首席执行官林登·赖夫说：“如果你有选择使用清洁能源而不是污染能源的机会，并且支付更少的钱，难道你不会选择这样做吗?”由此可以推知，他想说的是“有这样好的机会，人们都会选择清洁能源”，故答案为C。
单选题     What does the author think of solar panels?
 
【正确答案】 C
【答案解析】最后一段指出美国不同地区的光照有很大差别，因此在阳光普照的拉斯维加斯的太阳能电池板总会比在多云的西雅图的电池板具有更高的发电率，也就是说太阳能电池板的发电率因地域而有所差异，C是对原文的同义转述，故为答案。由于各地区光照不同，太阳能并不适用于每个地区，故A错误。文中没有提到太阳能电池板会彻底取代化石燃料，故B错误。文章末尾提到，资金的赞助意味着人们不必花太多钱来追求环保，也就是说太阳能电池板的费用不再超出人们的接受能力，故D错误。
单选题     What's the main idea of the passage?
 
【正确答案】 A
【答案解析】本文主要说的是住宅太阳能的使用，A能体现出文章主题，故为答案。原文除了指出安装太阳能电池板的阻碍，也谈到了其解决途径，故B片面。文中没有介绍清洁能源的前景，故C错误。原文讲的是住宅太阳能的使用，D范围过大，故排除。