8 auroral adj. 北極光的；
9 bicameral a. 兩院制的,有兩個(gè)議院的；
10 bilateral a. 有兩面的,雙邊的,雙方的。
例句：
I strongly disagree with this amoral approach to politics.
我強(qiáng)烈不同意這種對(duì)政治采取非道德化的態(tài)度。
Early embryos of many species develop ancestral features.
許多物種的早期胚胎具有其祖先的'特性。
This ancestral species might have evolved at a time when the islands were connected.
這種祖先物種可能是在島嶼相連的時(shí)候進(jìn)化而來(lái)的。
Of today's different groups of algae, green algae are probably the most similar to ancestral plants.
在今天的眾多藻類中，綠藻可能與植物的祖先最為相似。