A new research shows human activity is changing the sound of the Earth's oceans and seas.Scientists say the sound changes of our oceans,seas,and other waterways affect many marine（海洋的）animals—from very small shrimps to huge whales.
Sound travels very far under water,Francis Juanes,an ecologist at the University of Victoria in Canada,told the Associated Press.For fish,he explained,sound is probably a better way to sense their environment than light.Sounds help fish and other marine animals communicate with each other.Sounds also help some ocean animals find food and avoid their hunters.
However,increased noise from humans is making it harder for these animals to hear each other.The noise is coming from shipping traffic,underwater exploration,and other noisy human activities.For many marine animals,their attempts to communicate are being masked（遮蔽）by sounds that humans have produced.Experts explain that masking happens when one or more noises in the water block sound important to a marine animal's living.The overall number of marine animals has gone clown by about half since 1970.Some studies show the stress from human noise might also affect the immune（免疫）system as well as reproductive health or behavior. "Imagine having to raise your kids in a place that's noisy all the time." said Joe Roman,a marine ecologist at the University of Vermont.
When people think of problems facing the ocean,we often think of climate change,plastics and overfishing.But noise pollution is another thing we need pay attention to. "Sound pollution may be easier to deal with than other ocean problems," Scientist Juanes says,"If we make nothing for the ocean,think about how to make it quieter."



Why is sound underwater important for ocean animals？ ______

A. It changes with light.
B. It travels very fast.
C. It helps them judge and contact.
D. It guides fishermen to find where they are.

What does Paragraph 3 mainly tell us？ ______

A. Underwater exploration must be stopped.
B. Kids should experience noise to be healthy.
C. Human noise brings stress to marine animals.
D. Marine animals have got used to sound changes.

What is the author's purpose to write the text？ ______

A. To introduce the benefits of sounds.
B. To show the effects of climate change.
C. To draw attention to sound pollution.
D. To share a method of studying ocean.

What will the author probably tell us in the following paragraph？ ______

A. How to deal with overfishing.
B. What is the main cause of climate change.
C. How to keep the number of marine animals.
D. What should be done to reduce sound pollution.