Various United Against Malaria campaigns are being launched in eight other African countries as well as in Britain and the United States to mark World Malaria Day on Sunday.

VOA: standard.2010.04.23

What you'll do is every day for the next 30 days give me one cent, next day two, four, eight and so on.

你们要做的是在未来30天给我一分钱，第二天二分，然后是四分，八分，以此类推。

哈佛公开课 - 幸福课课程节选

What you'll do is every day for the next 30 days give me one cent, next day two, four, eight and so on.

你们要做的是在未来30天给我一分钱，第二天二分，然后是四分，八分，以此类推。

哈佛公开课 - 幸福课课程节选