In order to do something meaningful, it’s necessary that you _______ determine what is really important.
The laboratory was well ______ for atomic research.
You must ______ a wide vocabulary if you want to learn a language well.
Don’t bother Tom, he is ______ with the experiment on water molecules in the lab.
Nowadays some parents regret not ______ more time with their kids when they were young.
Have you heard that he, as well as his parents, ______ visited the Summer Palace? —Really? No ______ he didn’t attend the meeting.