例句與造句

1. Now our eyes are about 7 times more sensitive to green light of the wavelength produced by green laserpointers than to sunlight.
2. It would, by definition take 200 seconds to deliver one Joule of energy; how long would that take to raise say a gram of paper or cloth to the point of combustion ( Fahrenheit 451 ? ), Are there super powerful laserpointers available?
3. It's difficult to find laserpointers in a sentence. 用laserpointers造句挺難的