The world's population(人口)is getting larger and larger,so scientists are trying to _______ new ways to solve the food problem.( )
catch up with
keep up with
come up with
make up with
The little boy is saving every coin he can buy his mother a present on Mother's Day.( )
even if
so that
as soon as
Look at the sign"No smoking".You smoke in public.( )
mustn't
needn't
wouldn't
As students,we have to follow the school rules and come to school .( )
next time
on time
in time
My father is the person influenced me most in my childhood.( )
who
when
which
Guizhou Huangguoshu Waterfall.Thousands of visitors come to visit it every year.( )
is in control of
is responsible for
is known for