cutting edge 同义词
knife edge
英文释义: 名词 the sharp cutting side of the blade of a knife
vanguard, forefront
英文释义: 名词 the position of greatest importance or advancement; the leading position in any movement or field; "the Cotswolds were once at the forefront of woollen manufacturing in England"; "the idea of motion was always to the forefront of his mind and central to his philosophy"
