她用火钳再夹一些煤放进炉子里.She used tongs to put some more coal on the fire.她用一把火钳往炉火上再加了一些煤.She used a pair of tongs to put some more coal on the fire.用这个火钳夹煤一点也不困难,顺手得很.It's very convenient to use this pair of fire - tongs to...
我们有时也用离岸价或成本加运费价.Sometimes F . O . B . and C & F are also employed.计算出可行解区域每一角点之利润 ( 或成本 ).Compute the profit ( or cost ) at each of the feasible corner points.你的目标是成为世界一流的, 创新的, 或 成本效益?Are you aiming to be world class, ...