Of course Regina could have chosen to ride a tried-and-tested elephant, camel, or even ostrich.
当然，其实除了牛，瑞加娜还有很多选择的，比如已经被验证成功的大象、骆驼，甚至鸵鸟。
2
But as you can see, astronomers have some pretty triedandtested methods for measuring distances in the Universe.
但是正如你所看的，天文学家已经有一些很好的尝试和测试宇宙长度的方法。
3
What are some triedandtested ways of implementing security, ensuring performance, compliance with standards for interoperability, designing for change?