这次延误完美地说明了我们为何需要一个新的计算机系统。

This delay is a perfect ___illustration of why we need a new computer system.

包含了几个例子，以作说明。

A couple of examples are included, by way of ___illustration.

这句话很好地说明了她对生活的基本态度。

This quote is a good ___illustration of her general attitude towards life.