At the edge of the grassland,there is a sign which says,“( )the grass”A.keep up B.keep away C.keep off D.keep back该题为什么不能选D（阻止）

At the edge of the grassland,there is a sign which says,“( )the grass”A.keep up B.keep away C.keep off D.keep back该题为什么不能选D（阻止）
At the edge of the grassland,there is a sign which says,“( )the grass”
A.keep up B.keep away C.keep off D.keep back
该题为什么不能选D（阻止）

At the edge of the grassland,there is a sign which says,“( )the grass”A.keep up B.keep away C.keep off D.keep back该题为什么不能选D（阻止）
keep back 意为：退缩; 隐瞒; 留下; 阻止.而题意是那个示牌写着“不要靠近草地”,故应选C,keep off避开; 不(让)接近.B的keep away 后应跟from

这里根据句意就可判断出不是“阻止草地”，而是“远离草地”啊。