比上不足,比下有余 worse off than some , better off than many ;
fall short of the best, but be better than the worst
不打不成交 No discord , no concord
不到长城非好汉 He who has never been to the Great Wall is not a ture man .
不到黄河不死心 refuse to give up until all hope is gone
不登大雅之堂 not appeal to refined taste
不费吹灰之力 as easy as blowing off dust
不分清红皂白 indiscriminately
不敢越雷池一步 dare not go one step beyond the prescribed limit
不可同日而语 cannot be mentioned in the same breath