初三牛津英语词组.

life on Mars
look after
in the form of
play guitar
by twenty one hundred
get more and more crowded and polluted
at half speed of light
three eighths
choose from
compare.with...
plenty of
prevent sb from doing
under the control of
provide sb with sth
on the surface of ...
compressed food
realize
be harmful to
calm down
take off
begin with a discussion
make the robot do our homeworks