你做做好事,给我沏杯茶吧。 Be an angel and make me a cup of tea.
做做好事,把那本书给我吧。 Be a dear and (ie Please) give me that book.
在美国,做好事有如爱国主义一样,已成了推销某些东西的人们爱用的一种手段。 In the United State, do good have come to be, like patriotism, a favourite device of persons with something to sell.