---- Susan, go and join your sister cleaning the yard.  ---- Why ____? John is sitting there doing nothing.

(2013·高考浙江卷)Half of ________ surveyed in 16 countries say they go first to their closest friend to share their deepest wishes and darkest fears.

Make sure you’ve got the passports and tickets and _________ before you leave.

 _____ is the population of your country?

 Computers must be of great use to ________ doing the scientific research.