
Deep under the Pacific Ocean lie coral reefs colored by some algae that live with corals. Corals usually provide nitrogen (氮) to algae, and in return they get carbon (碳), which gives them energy.
In the early 1980s, a huge heat wave turned more than 90 percent of these corals a pale, lifeless white. And it was believed that about 50 percent of reefs with beautiful corals might disappear by 2030. Heat waves warmed up the same Pacific waters in the late 1990s and again in 2015—2016, but scientists noticed that these heat waves didn’t influence the reefs as badly as the first. Maybe corals have found a way to adapt (适应).
Swimming to cooler waters is not a good choice for corals, for it makes them easily hurt by the changing climate. But corals are able to adapt. Some turn to those algae that can deal well with heat. Others can use rows of tiny hairs on their bodies to “fan” away too much harmful oxygen (O2) let out by stressed-out algae. Certain baby corals change their own metabolisms (新陈代谢) in order to fight the warming waters. But all these adaptations can protect themselves only to some degree.
After studying and understanding these adaptations, scientists are trying to find ways to help corals fight. If researchers can make corals accept algae that can deal with heat pressure or if they energize genes (基因) that can deal with heat pressure, it will raise the corals’ chance of living through future ocean heat waves.
“When I go down to the sea and see a beautiful healthy reef with these colorful corals, I feel this pleasure of being in this underwater world,” a famous biologist says. “It will be really sad to see it dead. But that does drive you to want to use your skills and your love to help fight.”
1.1.What can we know from paragraph 1?
A Corals make algae more colorful.
B Algae provide room for corals to live in.
C Corals and algae depend on each other.
D Algae produce nitrogen to influence corals.
解析:选C。推理判断题。第一段提到珊瑚为藻类提供氮,而藻类为珊瑚提供碳,这是一种互利共生的关系,因此C项“珊瑚和藻类相互依赖”正确。
2.2.
A The heat wave in the early 1980s.
B The heat wave in the late 1990s.
C The Pacific waters in 2015—2016.
D The reefs’ disappearance by 2030.
解析:选A。词义指代题。第二段提到,20世纪80年代初的热浪导致珊瑚白化,而90年代末和2015-2016年的热浪对珊瑚的影响较小,因此“the first”指的是20世纪80年代初的第一次热浪,故选A。
3.3.What difficulty do corals face?
A They cannot completely adapt to heat waves.
B They cannot change their own metabolisms.
C They have no ability to swim to cooler waters.
D They have no ability to drive away harmful oxygen.
解析:选A。推理判断题。第三段提到珊瑚可以通过多种方式适应热浪,但这些适应方式只能在一定程度上保护自己,说明它们无法完全适应热浪,因此A项正确。
4.4.What can we infer from the last paragraph?
A It’s necessary to live with corals.
B The ocean has become unhealthy.
C We should try our best to save corals.
D Making a study of the ocean is a must.
解析:选C。推理判断题。最后一段中,生物学家表达了对珊瑚礁消失的担忧,并强调要利用自己的技能和热爱去帮助珊瑚,因此可以推断我们应尽力拯救珊瑚,故选C。
5.5.Which would be the best title for the text?
A Corals Die Out
B Corals Fight Back
C Corals Break Down
D Corals Come into Being
解析:选B。主旨大意题。文章主要讲述了珊瑚在面对热浪时的适应能力以及科学家为帮助珊瑚生存所做的努力,因此B选项“Corals Fight Back”(珊瑚的反击)最能概括全文主旨。