托福阅读

❓ 题目 According to the passage, what is the primary reason the hydra can achieve biological immortality?

A. A) It possesses a unique genetic mutation that halts all cellular aging.
B. B) Its interstitial stem cells continuously replace differentiated cells, preventing damage accumulation.
C. C) It has no predators or diseases in its natural environment.
D. D) Its stem cells remain quiescent permanently, avoiding replication errors.

B) Its interstitial stem cells continuously replace differentiated cells, preventing damage accumulation.

📝 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

TOEFL Score Builder