中译英一句，在线等，送30分，谢谢

应该是1：8吧

By mutual consent,the contract was signed based on the the exchange rate of 1 to 8 between US dollar and RMB.

B The two sides agreed to the signing of this contract, one eighty dollar and the RMB exchange rate for clearing standards

one dollar and the eighty RMB exchange rate for clearing standards was agreed by the two sides to sign the constract

The two sides A and B agreed to the signing of this contract,and take the dollar and RMB exchange rate at 1:80 for clearing standards.

The two parties,taking the exchange rate between the US dollar and RMB 1:80 as settlement standard, agreed to sign this contract.