我们很抱歉我们有两件事情不明白
（1）We are so sorry there are two things that stay so obscure to us
（2）We are so sorry to have two things that can't be understood by us
（3）We are very sorry that there are two things that are so ambiguous to us
（4）We are so sorry with two things to be confirmed further with you
第一我们之前的定单 A型号是B链条.C型号是D链条.麻烦请确认我们需要询问的型号,
The first is to refer to the thing that the Model A in our previous order is Chain B,Model C is the Chain D ,Please take your trouble to confirm the Model No.we need again ,Thanks a lot !