"I think the world need to understand that this is the new challenge of the 21st century, and this is the new war,"

VOA: standard.2009.05.10

Are you among those more comfortable, have you taken any computer science, were you programming at the age of 10 but you'd actually like to learn a bit about things you don't yet know and challenge yourself with new content or are you somewhere in between?

你对电脑比较熟悉么，你上过计算机专业方面的课程吗？,你是不是10岁就会编程,来上课的目的只是为了学习未知的知识,或者用新知识来挑战战自我？,还是二者兼有？

哈佛公开课 - 计算机科学课程节选

"Tea is the world's second most popular drink, second to water, and there are literally thousands of tea formulations around the world, so the challenge for us, isn't finding new tea recipes, it's focusing and making sure we're developing things that are going to work."

VOA: standard.2010.02.17