A:Why don't you sign the contract?

　　你们为什么不签合约?

　　B:A contract cannot arise out of an illegal act.

　　违法行为不能构成合约。

　　A contract cannot arise out of your requirment.

　　你的要求不能构成合约。

　　A contract cannot be made up of an illegal act.

　　违法行为不能构成合约。

　　A contract cannot be formed of an illegal act.

　　违法行为不能构成合约。

　　延伸阅读:

　　A:When a contract is established?

　　合同什么时候成立？

　　B:A contract is established when the acceptance becomes effective.

　　承诺生效即合同成立。

　　A contract is established when the acceptance goes into effect.

　　承诺生效即合同成立。

　　A contract is established whe the acceptance comes into force.

　　承诺生效即合同成立。

　　When the law becomes effective?

　　法律什么时候生效？