19.保持稳定：Level out，do not change，remain stable，remain still，remain steady ，be stable，maintain the same level，remain unchanged，be still，remain the same level，stay constant，keep at the same level，level off，stabilize ，keep its stability，even out
20.急剧地：Dramatically，drastically ，sharply，hugely，enormously，steeply，substantially，considerably，significantly，markedly ，surprisingly，strikingly，radically，remarkably ，vastly，noticeably
21.平稳地：Steadily，smoothly，slightly，slowly，marginally ，gradually，moderately ，mildly
22.宣称：Allege, assert, declare, claim 
23.发生：Happen, occur, take place 
24.原因：Reason, factor, cause
25.发展：Development, advance, progress
26.有益的：Useful, helpful, beneficial , profitable, rewarding， advantageous
27.影响：Influence, impact, effect
28.明显的：Clear, obvious, evident, self-evident, manifest , apparent, crystal-clear
29.占：Comprise, take up, account for, constitute, consist of, make up, occupy, hold, compose 
30.与…相比：Compared with，compared to，in comparison with，in comparison to，by comparison with，by comparison to
31.对比而言：By contrast，in contrast，on the other hand，on the contrary，conversely 
32.展示：Show, reveal, illustrate , demonstrate, depict, present, represent, describe
33.大约：Approximately ，almost，about，around，nearly，roughly
34.波动：Fluctuate，go ups and downs，display a fluctuation，demonstrate a fluctuation
35.事实上：Practically，in practice，essentially ，in essence，in reality，in effect，in fact，as a matter of fact，it is a fact that
36.换言之：Namely，that is to say，in other words，to put it like this，to put it differently，to put it from another way，to put it from another angle