Admittedly, not all animal experimentations are cruel. Some simple and pain-free experiments can benefit both mankind and other animals. For instance, some efforts which aim at increasing the group number of some endangered species can provide opportunities for them to thrive again on the earth so that they can share with mankind this beautiful world. Such kind of experiments should be encouraged.

我们无法改变过去，我们只拥有现在和将来。过去的已经过去了，包括那些为人类科技进步而遭受了无尽痛苦甚至牺牲了宝贵生命的动物们。我们需要谨记的一点是：当我们在考虑人类自身利益的时候，也替其它动物们想一想。

We can not change the past. We only have the present and the future. What is gone is gone, including those animals that had suffered great pains and even sacrificed their precious lives for the scientific and technological progress of mankind. However, we should bear in mind that while we are thinking about our own benefits, we should also have other animals in mind.