They just cared about the cost. They didn't care about usability.

他们只关。他们不关可用性。

The stools were made as a project whose goal was to explore the usability of various waste products.

这些艺术品凳子是一个探索各种废物再利用的项目。

It's reaching the end of its lifetime — and there have been extensive studies to extend the usability of the Thames barrier.

它的使用寿命即将结束——人们对泰晤河护栏的可用性进行了广泛的研究。

And the app that I have found to be the absolute best combination of features and usability, personally at least, this is my opinion, is called Noteshelf 2.

而我认为是功能和可用性完美结合的应用程序，至少就我个人而言，这是我的，做Noteshelf 2。

Beyond the scientific parts, there are a lot of usability issues to be taken into consideration: for instance, the algorithm should notify the user when a given guide is not to be used anymore and can be safely erased.

除了技术理论上的问题，还有些实际使用上的问题需要考虑：例如，算法应该能够告知用户某条辅助线已经不再使用、可以擦掉了。