鞭长莫及

beyond the reach of one's power
too far away for one to be able to help

庇佑, 碧玉, 闭元音, 避孕, 臂章, 币值, 币制, 避重就轻, 敝帚自珍, 壁助, 篦子, 跛足, 笾, 边, 鞭, 蝙, 编, 砭, 边币, 鞭策, 编程, 鞭笞, 鞭虫, 边陲, 编次, 鞭打, 编导, 边地, 编队, 边防, 边锋, 蝙蝠, 编号, 鞭痕, 编辑, 编辑室, 边际, 边疆, 边角科, 边界,