key sector的用法和樣例：
例句
- He revealed that half the officers in a key unit failed a polygraph test last year.
據他透露，半數某關(guān)鍵部門(mén)的警官都沒(méi)能通過(guò)去年的測謊鑒定。 - Since its inception, PDC has expanded at a rapid pace and is now a key department for delivery of banking systems within the HSBC Group.
自成立以來(lái)，軟件開(kāi)發(fā)中心高速發(fā)展，現已成為匯豐集團銀行系統的關(guān)鍵部門(mén)。
