sustain
维持,维系(强调长期持续性,不让它停下来)
maintain
维持(强调保持某一水平或状态不变)
The country has managed to sustain impressive economic growth over three consecutive decades despite significant regional instability.
尽管面临严峻的地区不稳定,该国在连续三十年间成功维系了令人印象深刻的经济增长。
Schools must work hard to maintain consistent academic standards across all year groups and subject areas.
学校必须努力在所有年级和学科领域维持一致的学术标准。