Passage Two
The lion may be the most famous of all the predators of Africa, but one of the most fascinating is the wild dog. Wild dogs are fairly small, averaging seventy pounds, with round, fanlike ears that look too big for their heads. They have shaggy brown coats with scattered patches of white. One of these animals by itself looks harmless or even comical. But when they band together, in packs of up to forty, the wild dogs become dangerous predators that tirelessly run down and kill animals that are many times their own size.
Wild dogs have to be good hunters in order to feed their large families; a single female can have as many as sixteen pups at a time. But usually only one female in a pack breeds at a time, and all the pack members help to care for the young. At first, the pups feed on their mother’s milk. Then the other dogs begin to bring back meat from the kill, carrying it in their stomachs and throwing it up when the pups come running to
A. are very fierce
B. hunt in large packs
C. are very intelligent
D. have unusually large litters
Passage Two
The lion may be the most famous of all the predators of Africa, but one of the most fascinating is the wild dog. Wild dogs are fairly small, averaging seventy pounds, with round, fanlike ears that look too big for their heads. They have shaggy brown coats with scattered patches of white. One of these animals by itself looks harmless or even comical. But when they band together, in packs of up to forty, the wild dogs become dangerous predators that tirelessly run down and kill animals that are many times their own size.
Wild dogs have to be good hunters in order to feed their large families; a single female can have as many as sixteen pups at a time. But usually only one female in a pack breeds at a time, and all the pack members help to care for the young. At first, the pups feed on their mother’s milk. Then the other dogs begin to bring back meat from the kill, carrying it in their stomachs and throwing it up when the pups come running to
A. Africa's Wild Dogs
B. Killers of the Plains
C. Predators of Africa
D. The Greedy Lion
Passage Four
Archimedes was a famous Greek mathematician and scientist. He was born around 287 BC and he died in the year 212 BC.
Archimedes is most well-known for one specific idea that he came up with. "Archimede’s Principle" states that a solid object which is immersed in a liquid is pushed up by a force which is equal to the weight of the water that the object moves. For example, if you put a piece of wood and a piece of gold the same size in water, only the wood will float. Both the wood and gold move the same amount of water, but the wood weighs less than this water, while the gold weighs more.
It is believed that Archimedes discovered this principle when the king of Syracuse asked him to solve a problem. The king wanted to know if his crown was pure gold or a mixture of gold and silver. The king, of course, did not melt his crown to find out. The idea came to Archimedes as he lowered himself into his bath. He noticed how the w
A. D．Archimedes did the experiment on his crown c;a;b;dB.b;c;a;dC. b;c;d;aD. c;a;d;b
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