sign change

例句：

1. 2.
   在法律或合同中
2. 3.
   在通信或文件上
3. 1. The company has decided to sign a new contract with the supplier.
   公司已决定与供应商签订新合同。
4. 2. The document was signed by both parties before it was sent out.
   这份文件在发出之前由双方签署。
5. 3. Before signing the agreement, they reviewed all the terms and conditions.
   在签署协议之前，他们审查了所有条款和条件。