a written contract的用法和样例：
- He produced a written contract under seal.
- A written contract or certificate of insurance.
- You must sign a writing contract with your company.
- Herewith we are sending you a written contract under seal in two copies.
- Where a license to exploit a layout-design is given to others, the parties shall conclude a written contract.
- If he agrees, make him sign a written contract at once that spells out the terms.