填空题

Over 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 David Irvine-Halliday.
In the late 1990s, the Canadian (36) was working in India when his return flight was (37) . A delay gave him time to take a 14-day hiking (徒步旅行) trip around the country.
One day he looked in the window of a school and (38) how dark it was. This is a common problem for (39) of children around the world.
Many families use kerosene oil lamps (煤油灯). There are many problems with these lamps. They produce only a small (40) of light. They are dangerous to (41) . And they are a big fire danger, causing many (42) and deaths each year. Kerosene costs less than other forms of lighting, but it is still (43) in poor countries. (44) . Finally, he decided to use a bright white LED made in Japan.
(45) . His Light Up the World Foundation has now equipped the homes of 25,000 people in 51 countries. Now his aim is to develop a lower-cost lighting system. (46) . Over 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 David Irvine-Halliday.
In the late 1990s, the Canadian (36) was working in India when his return flight was (37) . A delay gave him time to take a 14-day hiking (徒步旅行) trip around the country.
One day he looked in the window of a school and (38) how dark it was. This is a common problem for (39) of children around the world.
Many families use kerosene oil lamps (煤油灯). There are many problems with these lamps. They produce only a small (40) of light. They are dangerous to (41) . And they are a big fire danger, causing many (42) and deaths each year. Kerosene costs less than other forms of lighting, but it is still (43) in poor countries. (44) . Finally, he decided to use a bright white LED made in Japan.
(45) . His Light Up the World Foundation has now equipped the homes of 25,000 people in 51 countries. Now his aim is to develop a lower-cost lighting system. (46) .