What does the word“defensive”mean in the passage?

What does the word "bottlenecks" （Para. 2) mean in this passage？A．A narrow part of a bottl

What does the word precursor in the context in the second paragraph mean？

What does the word "defensive" mean in the passage？ 查

What does the " unwanted deep sea life" mean in Paragraph 2 according to the passage？A．The

What does the word "altruism" in Paragraph Two mean？A．The quality of being optimisticB．The

What does the word "integration" in the last paragraph probably mean？A．Host countries coop