TEXT G First read the following questions. 83. The amount of solar energy that is absorbed as heat is _____. A. 19% B. 34% C. 53% D. 47% Now read Text G quickly and select your answers. Solar Energy 1. Sometimes your wet bathing suit dries before you have had a chance to change into your clothes. When seated by the window of a bus on a sunny winter day, you may feel very warm. These situations occur because solar energy is present. Solar energy is energy given off by the sun. 2. Imagine gasoline flowing over Niagara Falls at the same rate the water does. That would be 5 billion gallons (19 billion liters) of gasoline an hour! Suppose that all the flowing gasoline is collected for over 200 million years. If all that gasoline is burned, it would equal the amount of energy transmitted by the sun in one hour. 3. Not all the solar energy released by the sun reaches the earths surface. About 34% is scattered into space by the gases or dust in the atmosphere. Another 19% is absorbed by the different layers of the atmosphere. The remaining 47% finally reaches the ground where it is absorbed as heat.

　　83. The amount of solar energy that is absorbed as heat is _____.

　　A) 19%

　　B) 34%

　　C) 53%

　　D) 47%

　　TEXT H First read the following questions. 84. Pharmacologists and biologists are interested in sponges because _____. A. they are primitive B. of their digestive system C. of the chemicals they produce D. they are neither plant nor animal Now read Text H quickly and select your answers. Sponges are just barely animals, such as a borderline case that until the 19th century they were called zoophytes, the animal-plants. They are among the most primitive forms of multi-cellular animal life. But they have been around a long time and must be doing something right. More than 5,000 species inhabit this planet, living in fresh water and throughout the sea down to depths of more than 25,000 feet. Often strikingly beautiful, sponges offer the added virtue of usefulness. Even with synthetic sponges widely available, a market for natural sponges persists. They hold more water without dripping, are easier to clean, and last longer, even under heavy use. And now, after centuries in the bathtub, sponges are finding their way into the laboratories of pharmacologists and cell biologists. As do so many marine invertebrates that have limited defenses in the usual sense (they are capable of neither fight nor flight), sponges produce some extremely powerful chemical compounds, toxic and otherwise, that hold great promise as future drugs for the treatment of human disorders, including cancer.

　　84. Pharmacologists and biologists are interested in sponges because _____.

　　A) they are primitive

　　B) of their digestive system

　　C) of the chemicals they produce

　　D) they are neither plant nor animal