SECTION B SKIMMING AND SCANNING
　　In this section there are five passages with a total of ten multiple-choice questions.    Skim or scan them as required and then select your answers to the questions.
　　TEXT F First read the following questions. 81. The authors main purpose in the passage is to _____. A. categorize tie different kinds of sharks B. warn humans of the dangers posed by sharks C. describe the characteristics of shark teeth D. clear up misconceptions about sharks 82. The longest shark is probably _____. A. the whale shark B. the great white shark C. the bull shark D. the tiger shark Now read Text F quickly and select your answers. Most people picture sharks as huge, powerful, frightening predators, ready at any moment to use their sharp teeth to attack unwary swimmers without provocations.
There are numerous fallacies, however, in this conception of sharks. First, there are about 350 species of shark, and not all of them are large. They ranger in size from the dwarf shark, which can be only 6 inches long and can be held in the palm of the hand, to the whale shark, which can be more than 55 feet long. A second fallacy concerns the number and type of teeth, which can vary tremendously among the different species of shark. A shark can have from one to seven sets of teeth at the same time, and some types of shark can have several hundred teeth in each jaw. It is true that the fierce and predatory species do possess extremely sharp and brutal teeth used to rip their prey apart; many other types of shark, however, have teeth more adapted to grabbing and holding than to cutting and slashing. Finally, not all sharks are predatory animals ready to strike out at humans on the least whim. In fact, only 12 of the 350 species of shark have been known to attack humans, and a shark needs to be provoked in order to attack. The types of shark that have the worst record with humans are the tiger shark, the bull shark, and the great white shark. However, for most species of shark, even some of the largest types, there are no known instances of attacks on humans.
　　81. The author's main purpose in the passage is to _____.
　　A) categorize tie different kinds of sharks
　　B) warn humans of the dangers posed by sharks
　　C) describe the characteristics of shark teeth
　　D) clear up misconceptions about sharks
　　82. The longest shark is probably _____.
　　A) the whale shark
　　B) the great white shark
　　C) the bull shark
　　D) the tiger shark