proof

The detail of her wildlife paintings is (a) testament to (= proof of) her powers of observation. 她画野生动物十分细致，这证明她有很强的观察能力。

a will that someone makes, saying what should be done with their money and property after they die

This article will give clear instructions for making a last will and testament. 这篇文章清楚介绍了如何立下遗嘱。