1 . Turtles have a habit of eating plastic objects floating in the sea, which may kill them. Many believe that it is because floating plastic bags look similar to jellyfish, which many types of turtles love to eat. However, lots of plastic objects that turtles eat do not look like jellyfish at all. Joseph Pfaller of the University of Florida doubts that the smell of sea micro-organisms（微生物） which live on floating plastic objects attract turtles to eat.
The kind of idea first appeared in 2016. Researchers at the University of California, Davis, noticed that certain chemicals, especially dimethyl sulphide（二甲基硫）, which can be found on plastics where micro-organisms live, are those which many seabirds sniff（嗅）to find food. These birds are more likely to eat plastics.
Since turtles usually appear above the sea surface and sniff the air when going to their feeding areas, Dr. Pfaller believed that they are following these same chemicals like those seabirds and mistakenly think that floating plastic objects are edible.
To test that idea, he and his team did an experiment using loggerhead turtles. They exposed 15 turtles to four smells: the smell of clean water; the smell of turtle-feeding food; the smell of a clean plastic bottle; and the smell of a bottle that had been kept in the ocean for five weeks to allow micro-organisms to grow on it. When sniffing both the smell of turtle-feeding food and that of five-week-old bottles, turtles kept their noses out of the water more than three times as long, and took twice as many breaths as they did when sniffing the smell of fresh bottle-plastic or clean water.
Though they have not yet tested whether dimethyl sulphide on the five-week-old bottles cause turtles to eat plastic objects, Dr. Pfaller and his team think it is highly possible.
1. Which of the following is closest in meaning to the underlined word "edible"?| A．pleasing the eyes | B．suitable for use as food |
| C．holding the attention | D．concerned with actual use |
| A．Seabirds prefer the smell of the plastic bottles. |
| B．Seabirds feed on the food similar to the turtles'. |
| C．Seabirds produce a certain micro-organism. |
| D．Seabirds break up the plastics without difficulty. |
| A．To suggest a new way to study turtles. |
| B．To stress the importance of sea protection. |
| C．To introduce the findings on the cause of turtles' death. |
| D．To discuss the overusę of the plastic bottles. |
| A．Education. | B．Entertainment. |
| C．Science. | D．Health. |
2 . Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately：the air you breathe.
Previous studies have linked high exposure (暴露) to environmental pollution to an increased risk of heart problems，but two analyses now show that poor air quality can lead to heart attack or stroke (中风) within as little as a few hours after exposure. In one review of the research, scientists found that people exposed to high levels of pollutants (污染物) were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency (EPA)considers to be of “moderate” (良好) quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.
The authors of both studies stress that these risks are relatively small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure. However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulation by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.
1. The text mainly discusses the relationship between ________.| A．heart problems and air quality |
| B．heart problems and exercising |
| C．heart problems and smoking |
| D．heart problems and fatty food |
| A．relatively high | B．extremely low |
| C．relatively low | D．extremely high |
| A．Eating fatty food has immediate effects on your heart. |
| B．The EPA conducted many studies on air quality. |
| C．Moderate air quality is more harmful than smoking. |
| D．Stricter regulations on pollutants should be made. |
| A．inform | B．persuade |
| C．describe | D．entertain |
