n.someone who takes the place of another person

同義詞：surrogatereplacement

v.

go back and forth; swing back and forth between two states or conditions

同義詞：jump

exchange people temporarily to fulfill certain jobs and functions

be an understudy or alternate for a role

同義詞：understudy

reverse (a direction, attitude, or course of action)

同義詞：interchangetackswitchflipflip-flop

do something in turns

同義詞：take turns

1. The alternates in the competition were ready to step in if needed.
   比賽中的替補(bǔ)選手已經(jīng)準(zhǔn)備好在需要時(shí)替換上場。
2. The team alternates between defense and attack strategies during the game.
   在比賽中，隊(duì)伍在防守和進(jìn)攻策略之間交替進(jìn)行。
3.