B：Were you able to quote on all the items we need ?
      我们需要的每个项目你都能报价吗。

A：No, not all of them .
      不，没办法全部。

B：Oh ?why not ?
      哦，为什么？

A：We aren‘t able to supply the third ad fifth items .
      第三及第五项目，我们没有货供应。

1. 第五
    The fifth item in a series is the one that you count as number five.

    e.g. Joe has recently returned from his fifth trip to Australia.
           乔最近结束了第五次澳大利亚之行归来。

2. 五分之一
    A fifth is one of five equal parts of something.

    e.g. India spends over a fifth of its budget on defence.
           印度的国防开支占了其财政预算的 1/5 强。