change down

US /tʃeɪndʒ daʊn/
UK /tʃeɪndʒ daʊn/
"change down" picture
1.

换低档, 减速

to shift to a lower gear in a vehicle

:
You need to change down when going uphill.
上坡时你需要换低档
The driver had to change down quickly to avoid stalling.
司机不得不迅速换低档以避免熄火。