墨尔本文波雅思PTE的小编发现，PTE的re-tell lecture/ summarize spoken text很多同学听不懂是因为背景知识完全不知道，还有一些专业词汇不认识，今天小编给大家做一个科学知识科普专题1。帮助大家能够在没有听懂的情况下也能“蒙混过关”。
The most devastating coral bleaching event the world has ever seen is underway on the Great Barrier Reef. Australia’s preeminent scientists, conservationists and tourism operators warn this event points to the end of coral reefs worldwide unless change is made.
devastating: if you describe something as devastating, you are emphasizing that it is very harmful or damaging, e.g. Affairs do have a devastating effect on marriages.毁灭性的
underway: if something is underway, it is happening now. e.g. Economic recovery is already underway.在进行中
preeminent: means more important or powerful than all others, e.g. He was the preeminent scientist of his day.卓越的
Stressed coral turns an unnatural shade before it is bleached completely.
Bleached coral in Papua New Guinea.
What is coral bleaching?
Coral hosts tiny algae/’ælɡədʒiː/ in its tissues called zooxanthellae /zəuəuzæn’θeli:/ that produce its food as well as its colour.
When waters become too hot or cold, the coral becomes stressed and its metabolism /mɪ’tæbəlɪz(ə)m/ and reproductive system break down.
At this point, it cannot process the oxygen created by the zooxanthellae, so it expels them.
If the temperature returns to normal, these tiny creatures can re-enter the tissues, or if most but not all algae have been expelled, the remaining few can keep the coral alive.
If the temperatures remain extreme and the sun continues shining, the coral dies.
“Coral bleaching is the most visible example of climate change,” World Wildlife Fund’s Rick Leck said.
“Coral reefs are amazing in their ability to recover if you take away the threats that are causing their degradation,” Leck said.
“If we take action on renewable energy, if we reduce the pollution that’s flowing to the reef and we invest in those systems we know can work, then the reef can recover.
“It may take years, it may take decades but it will recover and that’s what we need to be working towards.”
P.S. 最后两张图大家可以用来练习PTE Decribe Image！！！