zhè jià / jiào liàn jī / yǐ jīng / fú yì / le / èr shí nián / xiàn zài / bèi / yòng zuò / jiào xué / zhǎn shì

这架教练机已经服役了二十年，现在被用作教学展示。

This trainer aircraft has been in service for twenty years and is now used for instructional demonstrations.