More than 1.5 billion people around the world live without electricity. Finding better ways to bring light to the poor is the goal of researchers like Professor Irvine. In the late 1990s, he was working in Nepal when his return flight was canceled. A delay gave him time to take a fourteen-day hiking trip in the Himalayas.
One day he looked in the window of a school and noticed how dark it was. This is a common problem for millions of children around the world. Many families use kerosene oil (煤油) lamps. There are many problems with these lamps. They produce only a small amount of light. They are dangerous to breathe. And they are a big fire danger, causing many injuries and deaths each year. Kerosene costs less than other forms of lighting, but it is still costly in poor countries. Professor Irvine says many people spend over 100 dollars a year on the fuel.
When he returned to Canada, he began researching ways to provide safe and clean lighting. He began experimenting with light-emitting diodes (发光二极管), LEDs, at his lab. As a professor of renewable energy, he already knew about the technology. Light-emitting diodes are small glass lamps that use much less electricity than traditional bulbs (灯泡) and last much longer. He used a one-watt bright white LED made in Japan. He found it on the Internet and connected it to a bicycle-powered generator (发电机). He remembers thinking it was so bright that a child could read by the light of a single diode.
In 2000, after much research and many experiments, he returned to Nepal to put the systems into homes. Now the homes of 25,000 people in 51 countries have been equipped with it. “The one-time cost of our system which basically lives forever, as well as the solar panel — is less than one hundred dollars. So, one year of kerosene would pay for a solid-state lighting system,” he said. Now his aim is to develop a lower-cost lighting system. In January, Irvine is leaving the University of Calgary. He has also decided to start his own company in India.
We can learn from the second paragraph that kerosene oil lamps ______.

A．cost more than other forms of lighting

B．have damaged children’s eyesight

C．have wasted only a little fuel

D．have a lot of disadvantages

Irvine connected a white LED to a bicycle-powered generator to prove ______.

A．whether it can work without electricity

B．whether it can work well with less electricity

C．whether it can last longer than a generator

D．whether it is brighter than a traditional bulb

We can learn from the text that Irvine ______.

A．likes India rather than Nepal

B．is good at making new kinds of bulbs

C．is giving up his job in the university

D．is to earn much money from his company