英语翻译XXX,很抱歉,我们的prototype(手板)在7月16号的时候不能完成了,因为之前那家供应商说做不出来,我们找了另外一家,手板会在下周一（7月21号）的时候做好.很抱歉.XXX

I have to apologize that we cannot delivery the prototype on July 16 for the supplier cannot fuuly produce on time. We have cooperated with another supplier and promised to deliver goods on next Monday (July 21).
We are so sorry.
Sincerely Yours,
XXX

XXX, I'm sorry, our prototype (Palm) when in July 16th can not be completed, because before that suppliers do not come out, we find another home, hand in next Monday (July 21st) when do. I'm sorry. XXX

I'm sorry, but our prototype (hand) did not finished in July 16th, because the supplier says do not to come out, we find another and hand will be on Monday (July 21)
I'm so sorry

xxx
Sorry that the prototype will not be finished on July 16th, because the supplier is not able to work it out. We have already get in touch with another supplier and they could provide the prototype for us on next Monday, July 21th.
Really sorry for this bothering.
Kind regards,
xxx

Dear XXX.I‘m sorry for telling you that our prototype can't finish to product on 16 Jul due to the before supplier said that they can't make this type of prototype. But we found another supplier, so ...

xxx
I'm very sorry.our prototype can't finish in July 16th，Because before that suppliers do not come out. We have found another home,prototype wil be finish July 21st.
I'm awfully sorry
xxx
纯手工翻译，保准正确，采纳吧(*^__^*) 嘻嘻……

XXX,
Sorry to inform you that our prototype can not finished on July 16. The supplier we cooperated before could not make it. We have found another instead. Prototype can be done next Monday(July 21).
希望采纳