Since the project has been ___ on well, you must ___ it on until it is completed.

Though Jack _______ many times, he still plays computer games after school.

Walmart, which is one of the largest American supermarket chains,         some of its store open 24 hours on Mondays through Saturdays.

—When are you leaving for Guangdong?—My plane        at six．

 We ___ our new neighbors yet, so we don't know their names.