keep away from;keep out;keep off;keep up的意思?

问题描述:

keep away from;keep out;keep off;keep up的意思?
We can often see the notice"_______ the grass" in the park.
A.Keep away from
B.Keep out
C.Keep off
D.Keep up
请问他们的意思分别是?

We can often see the notice"___C____ the grass" in the park.
A.Keep away from 远离
B.Keep out 使在外
C.Keep off 让开,不接近
D.Keep up 不低落,维持,继续