本合同由A公司(以下称之为“卖方)与B公司(以下称之为“买方)共同订立 鉴于卖方愿意

本合同由A公司(以下称之为“卖方")与B公司(以下称之为“买方")共同订立，鉴于卖方愿意依据下列规定的条款售卖下述商品，兹特立约为据，并由订约双方协议如下。

This contract is made by and between A Co. _____ called "the seller") and B Co.(_____ called "the buyer"), _____ the seller is willing to sell the buyer the commodities listed hereunder on the terms and conditions stipulated below. Now these presents witness that it is______ agreed between the parties hereto as follows.

A、hereof, hereof, whereas, therefore

B、hereinafter, hereinafter, whereas, hereby

C、whereof, whereof, whereby, hereby

D、thereafter, thereafter, whereby,thereinafter

请帮忙给出正确答案和分析，谢谢！