assembler error messages

例句：

1. 1. The engineer was the assembler who built the new machine.
   那位工程师是建造新机器的装配工。
2. 2.The carpenter is the assembler who assembled the furniture.
   木匠是组装家具的装配工。
3. 3. The assembler must be careful when assembling the parts.
   装配工在组装零件时必须小心。