托福阅读

❓ 题目 What is the main purpose of the passage?

A. A. To argue that the keystone species concept is outdated and should be discarded
B. B. To describe the history and ongoing relevance of the keystone species concept in ecology
C. C. To explain Paine's experiment and its immediate results in detail
D. D. To compare keystone species with functional redundancy in ecosystems

B. To describe the history and ongoing relevance of the keystone species concept in ecology

📝 免费在线练习

基于 700+ 托福真题题库 · 即时对错反馈

⚠️ 点击选项立即查看对错。建议先仔细阅读上方听力/文章再作答。

📝 题目：

加载中...

📚 托福备考推荐

Official TOEFL iBT Tests Vol.2