Ocean Noise Pollution The noise that affects sea creatures comes from a number of human activities. It is caused mainly by industrial underwater explosions, ocean drilling, and ship engines. Such noises are added to natural sounds. These sounds include the breaking of ice fields, underwater earthquakes, and sounds made by animals themselves. Some scientists have proposed setting a noise limit of one. hundred-twenty decibels in oceans. They have observed that noises at that level can frighten and confuse whales . Many researchers, whose work depends on ocean sounds object to a limit of one-hundred-twenty decibels. They say such a limit is a greater danger than they believed. They want to prevent noises from harming creatures in the ocean. A The sound of a car. C Man-made noise pollution.
连词的概念
比较can 和be able to
结果状语从句
关系代词that 的用法
should 和ought to的区别
wish的用法
并列连词与并列结构
地点状语从句
先行词和关系词二合一的应用
特殊的虚拟语气词:should
表示选择的并列结构
介词+关系词的应用
引导名词性从句的连接词
had better的用法
and 和 or 的区别
so和such的区别
方式状语从句
what/whatever;that/what; who/whoever的比较
would rather的用法
名词性从句的概念
判断关系代词与关系副词
名词性wh-从句
It is (high) time that的用法
关系代词引导的定语从句
情态动词表示推测的用法
否定转移的应用
as, which 非限定性定语从句
if, whether引导的名词从句
情态动词的语法特征
定语从句的概念
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