C. We should not be too shy to show our talents. D. The woods would be very silent without birds.
C ★★★☆☆
In 1985, a lionfish was caught off the coast of Florida. Now they can be found not only in the Atlantic Ocean but also in the Gulf of Mexico and the Caribbean Sea. And they are continuing to move south. Lionfish are native to the Indian and western Pacific Oceans. So how did they end up in the Atlantic? Scientists believe some pet owners abandoned their unwanted lionfish and poured them into the sea. Little did they know the trouble their actions would cause.
The Atlantic Ocean turned out to be a comfortable home for lionfish. Their venomous spines (毒刺) protect them from sharks and other fish. Female lionfish can spawn (产卵) every few days, producing as many as 2 million eggs per year. Other big fish would have competed with lionfish for food. But overfishing has removed many of these large fish. As a result, the fish have eaten so much that they have grown to be more than three times the size of their cousins in the Pacific and
Indian Oceans. “They eat mostly fish,” says Stephanie Green, a scientist at Oregon State University.
All that eating has caused great changes. Scientists have found that when lionfish are present somewhere, many other fish, which are small enough for them to eat, disappear. Some of the fish they eat are greatly missed in their habitats. For example, parrotfish eat certain plants off corals (珊瑚), which allows corals to grow better. But they are now disappearing due to lionfish.
Scientists say lionfish are here to stay. But there are ways to deal with the problem. The key, says Green, is to keep lionfish numbers in check. In Florida, divers can now go through a special training program and get certified (授予合格证书) to catch lionfish in areas where fishing is not usually allowed. And a number of restaurants have added the fish to the menu. “It’s going to be a long-term battle, but the missing sea species will come back someday,” says Green. 29. What can we learn about lionfish? A. Its population is growing very quickly. B. All of them are almost the same size. C. They eat other big fish and even sharks. D. Most of them have gathered in the Atlantic. 30. Parrotfish were mentioned to show lionfish’s _____. A. loneliness B. carelessness C. weakness D. harmfulness
31. What is Stephanie Green’s attitude towards the battle against lionfish?
A. She doubts it. B. She is hopeful of it.
C. She is worried about it. D. She thinks it is against the law.
D ★★★★☆
Google, the leading company in self-driving technology, has completely renewed its development program. Previously, Google had cars built by other companies, but now it will start building its own cars.
For the past four years, Google’s technicians had been working on a way to return control to the human driver’s steering wheel (方向盘) in a dangerous situation. However, Google now says that the switch from automation to human control will not be possible anytime soon. Google’s heads realized that relying on a human that may be reading, working, or sleeping to take over in an emergency wouldn’t work. So what’s the solution?
Google has started to build a series of 100 experimental electric cars that look like a Smart car or Fiat 500. The only difference? There is no steering wheel, gas
pedal (油门) and brake (刹车). The only things a human passenger controls are a red “e-stop” button for panic stops and a start button. The car’s face is designed to make it seem friendly and help people accept self-driving technology.
Google employees had taken part in a long experiment, in which they used self-driving vehicles to work every day. There were no crashes. This is a major change from competing self-driving projects. Mercedes Benz, BMW and Volvo have all developed some self-driving cars, but none completely eliminate the driver. For example, the Mercedes Benz cars will stop if the driver takes his hands off the wheel for over ten seconds.
Google will limit its early cars to a top speed of 25 miles per hour for safety reasons. These cars are designed to drive in or around cities, not on highways. However, a Google engineer commented that once their safety has been proven, there will be no limit to the speed. In the near future, Google’s self-driving cars may make our roads much safer, and of course drivers may feel more relaxed on the way. 32. Unlike a Smart car, Google’s electric cars _____. A. can run not only on land but also under water B. just offer two control buttons for a passenger C. are equipped with an unusual steering wheel D. are environmentally friendly and run faster
33. The underlined word “eliminate” in Paragraph 4 can best be replaced by “_____”.
A. train B. employ C. remove D. frighten
相关推荐：
loading