中国大学MOOC: The idea of a free trial period is often used to sell computer games, memebership of a club,ect.
举一反三
- 中国大学MOOC: Young children seem to master computer games ______ ease.
- 中国大学MOOC: —Do you like playing computer games?—No, but I .
- 中国大学MOOC: ______ invitation is often used in a business setting.
- 中国大学MOOC: Rising Tone is most often used in ________.
- 中国大学MOOC: The red clause credit is often used as a method of ( )