相关单词同义词hard, tough, 近义词 fussy, grim, hard, obscure, painful, steep, stiff, ticklish, tough, trying反义词easy, straightforward临近词difficulty, differentiate, difficult of, Difficultiea, difficultiesl, difficult job, difficultness, difficult man, Difficult ore, difficult task, difficult work, difficult test相似词differential calculus, differential gear, differentiate, differentiation, difficulty, diffident, diffract, diffraction, 返回 difficult