additional travel

例句：

1. 1. We need to add some more ingredients to the recipe.
   我们需要在食谱中加入一些额外的成分。
2. 2. The company has added an additional salesperson to its team.
   该公司已经增加了一名额外的销售人员到其团队。
3. 3. They added an additional layer of protection to the wall.
   他们给墙增加了一层额外的保护层。