Cars do cause people some health problems, in fact far more serious _____ than computers do. 

Nine in ten high school students say there are significant differences in their attitude toward chatting on line, compared with _________ of their parents. 

They were all very tired, but _______ of them took a rest.

Mr Smith is at the door. _______ wants to see you.

(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.