here
are
many
environmental
problemsthey
act
as
teachers.i
stop
the
baby
crying.it
cause
him
to
cry.let
me
in!the
tree
takes
in
water.you
have
many
bad
habits.don't
throw
them
away.
they
are
usefulyou
are
talking
all
the
way.in
order
to
p搜趣网ass
the
exam,
you
have
to
work
hard.

You
are
not
supposed
to
go
across
street
when
the
traffic
light
is
still
red.
你不应该在红灯还亮着的时候就过马路.
I
hav搜趣网e
no
idea
what
i
need
to
do
next
after
i
have
finished
all
of
my
tasks.搜趣网
我已经昨晚了我所有的功课,我不知道搜趣网我下一步该做什么.

你好We should keep/stop the factory from pouring the waste / polluted water into the rivers.keep stop prevent 均可加宾语再加from doing其中keep的from不可省略（省略以后意思截然相反，变成保持做某事）后两者可以省略from