add-on意思如下：
英/ˈæd ɒn/。美/ˈæd ɑːn/。
n.附加物;附加装置。
复数： add-ons。
Biodiversity is not an add-on.
生物多样性并不是一种附加物。
An Investigation to the Effects of Add-on Devices on Reducing Aerodynamic Drag of Domestic Trucks .
用空气动力学附加装置降低国产货车气动阻力措施的探讨。
The company offers scuba-diving as an add-on to the basic holiday price.
这家公司提供带水肺潜水活动，不包括在基本度假费用以内。
Speakers are sold as add-ons for personal stereos.
扬声器作为随身听的附加装置出售。
Considering cost and quality, there is optimal size add-on.
考虑成本与质量，存在最佳上浆率。
You can also create entirely new add-ons to suit your environment.
还可以创建全新的附件来满足您的环境的需求。
