语法总结
现在完成时与现在完成进行时
have been overfished / have been frightened / have caused 把长期趋势和当前结果都连接起来。
相似句：
- The river has been polluted for years.
- People have grown used to the noise.
not ... but ... 纠正误判
not sharks or killer whales, but cod and skate 把读者的第一反应纠正为真正答案。
相似句：
- It was not anger, but fear.
- She bought not tea, but coffee.
which 引导定语从句
varieties like cod and skate which grow to unnatural sizes 用从句补充异常生长事实。
相似句：
- The trees which grow here are very tall.
- He bought a car which uses little fuel.