1. tropical 热带(地区)的

Have you seen the brightly-coloured plumage of tropical birds?
你见过热带鸟类色彩斑斓的羽毛吗？

Her motherland is in the tropical region.
她的祖国位于热带地区。

2. immigrant 移民

Immigrant workers were classed as resident aliens.
移民来的工人已归入外侨类.

He admitted that he was an illegal immigrant.
他承认他是非法移民。

3. vast 广阔的,巨大的

A vast crowd turned out to watch the match.
大群的观众到场观看比赛。

The Pacific Ocean is a vast expanse of water.
太平洋是一片广大的水域。

4. fascinating 迷人的

The book is fascinating, despite its uninspiring title.
这本书很有意思, 虽然书名并不吸引人.

I find it extremely fascinating.
我觉得这非常迷人。