not natural or real, but made by people
artificial
the opposite to increase
decrease
we do it with rubbish
throw away
We did ... experiments at Chemistry lesson.
scientific
At the museum I saw lots of ... exhibits.
historical
find sth by chance
come across
computer equipment
hardware
I know everything about this
I am aware of this
we should drink ... 2 litres of water a day.
at least
when you do not have enough of sth
lack
this battle is important for our history, it's ...
historic
a lot of
a number of
There are a lot of ... on TV.
programmes
make a summary
make a conclusion
when sth doesn't work
be out of order
the programs you have on your computer
software
not usual
unique