4. When Mary finally got there, Tom had left an hour _____.
In order to finish the work on time, we can't __________ to waste a single minute.
__________ in her office for nearly 20 hours, she is going home to have a rest.
Thanks for your help, otherwise we would have __________ the game!
Jane __________ Betty is going abroad, so they help each other to prepare for the test.
There were nearly 3,000__________ in the concert hall.