Take the great American scientist Thomas Edison as an example. He tried experimentafterexperiment and had one failure after another before he finally invented the bulb.
以伟大的美国科学家托马斯·爱迪生为例，他做了一次又一次的实验，失败了一次又一次才最终发明了灯泡。
2
Overall, 201 high school students completed sleep habit surveys before and after the nine-week experiment last year.
总的来说，有201名中学生在去年历时九周的试验前后完成了关于睡眠习惯的调查。
3
Subjects had saliva samples and other measures of physiological stress taken at key points during the experiment - for example, before beginning the survey and after being asked to lie.