A:Why do you modify the contract?

　　你为什么变更合同？

　　B:A contract may be modified if the parties reach a consensus through consultation.

　　当事人协商一致即可变更合同。

　　A contract may be altered if the parties reach a consensus through consultation.

　　当事人协商一致即可变更合同。

　　A contract may be changed if the parties reach a consensus through consultation.

　　当事人协商一致即可变更合同。

　　You cannot modify the contract.

　　你不能更改合同。

　　延伸阅读:

　　A:A person is not liable for debts contracted during his minority.

　　一个人无须度it在未成年时期的合同债务承担责任。

　　B:What about the debts during his minority?

　　那在未成年时期的债务怎么办？

　　He should be liable for his fault.

　　他应该为他的错误承担责任。

　　She is too young to be liable for debts contracted.

　　她太小了不能对合同债务承担责任。

　　Who is liable for the fault?

　　谁为错误承担责任？