A ______ is a volume of space that is essentially empty of matter.
An alarm system can be a good _________.
I'm hoping my job will be made _________.
The _________ meet today.
A span of one thousand years is known as a __________.
Is it ___________ to park here?
There was great ___________ about whether to have a school tuck shop.
Older aircrafts require a lot of ___________.
Even the most reluctant spellers will find this website ____________.