We also had different students in some classes, so ______was a struggle to remember all the faces.

 A person _____ email account is full won’t be able to send or receive any emails.

—Which of these two dictionaries will you buy？ —I'll buy _____ ,for the different uses.  

(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.

They were all very tired, but ________ of them would stop to take a rest.