01 vital
vital 有两种既常见，又地道，且模板味儿又没那么重的用法：
be vital for / to sth 对...很重要
play a vital role in sth 在...中起重要作用
On June 1st Li Keqiang, the prime minister, seemed to signal a change, declaring that street vendors were vital to the economy.
02 pivotal
pivot 这个名词，是「中轴，中心，枢纽」的意思，形容词pivotal便可用来表示「中枢的；关键的」。
常见的搭配为：
be pivotal to sth
play a pivotal role in sth
Governments need to play a pivotal role in tackling climate change.
03 prominent
prominent 表示「显著的；突出的」
常见搭配：
played a prominent role in
04 indispensable
be indispensable for / to sth 对...来说很重要/不可或缺
play an indispensable role in sth 对...来说很重要/不可或缺
become an indispensable part in sth 成为...中必不可少的一部分
