芝加哥期货交易所大豆期货合约的最后交易日是交割月十五日的前一交易口。( )
参考答案：对
一 Good news! Bill won ______ medal in the long jump just now.
一 Really? That's his ______ one at our sports meeting. [ ]
A. a; four
B. an; fourth
C. a; fourth
“经纪人”理论
