trade for:
以...換得
The boy traded his knife for a football.
男孩用小刀換得一個足球。
What will you trade for the bugle?
你要我用什么東西來換你的喇叭?
exchange for:
1.交換,調換,兌換
They sold eggs in exchange for salt and tea.
他們把雞蛋賣掉換取茶葉和鹽。
The kid napers demanded money in exchange for her safe return.
綁匪們要求以金錢換取她的平安交還。
sign on
1.簽約受雇
He signed on as a sailor.
他簽約受雇為船員。
sign-on
名詞 n.
1.【廣播】開播