不易

not easy; difficult; hard; unchangeable; unalterable; not change easily; remain stable; be hard to change; with difficulty

重复

repeat; duplicate; replicate; replay; reprise; iterate; keep; echo; rehearse; reduplicate; do over; trot out; regurgitate; repeat yourself; repetitive; repeated; repetitious; constant; warmed-over; repeatedly; bis; repetition; rehearsal; redundancy; duplication; over and over again; over and over