1.date 确定年代

The skeleton has been dated at about 2000 BC.

这骨架的年代为公元前2000年左右o;O-cfpr[KH。

2.descendant 后代

These adaptations served their descendant well as they invaded land.

这些适应机制在它们的后代进化成陆生生物时起了很好的协助作用nc)vm42c2i[0%=。

3.upper limit 上限

Remember: there is no official upper limit to how much a person can spend in a lifetime.

记住，一个人一生能花多少钱，没有官方上限qMMC]J7^Wlb5cVLJ.。

4.a set of 一组

Most genes are regulated by a master set of genes.

大多数基因都是由一组主基因来调控的zv1DxdEP4Oz.m~M)jD。