Mom, the telephone is ringing. I guess either you or Dad on the phone.

Nearly three days after an 8．8-magnitude earthquake, rescuers in Chile were making every effort to _______ possible survivors．

A post office should be built in a central ______ for the sake of the convenience.

Students are encouraged to share their learning experience__________ their classmates.

The pen I _____ I_______ is on my desk, right under my nose.