The main idea of the first paragraph is that _____.
For (1) service, we need a virtual-circuit subnet. Let us see how that works. The idea behind virtual circuits is to avoid having to choose a new (2) for every packet sent. Instead,when a connection is established, a route from the(3) machine to the destination machine is chosen as part of the connection setup and stored in tables inside the (4) . That route is used for all traffic flowing over the connection, exactly the same way that the telephone system works.When the connection is released, the virtual circuit is also terminated. With connection-oriented service, each packet carries an (5) telling which virtual circuit it belongs to. 空白(3)处应选择()
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Have you ever thought about inventing something? Did you worry that your idea was too strange or unrealistic? Well, maybe you should think again.
Strange or unrealistic ideas never stopped Arthur Pedrick. Pedrick was a British inventor. Originally a government clerk, he spent his retirement in the 1960s and 1970s developing new and unusual ideas. Some of these ideas contradicted basic physics, but that didn’t stop Pedrick. One of his strangest ideas was a plan to connect huge tubes from the continent of Australia all they way to Antarctica, a distance of 10,000 Km! These tubes would carry giant ice balls from Antarctica to Australia. This ice would then melt in the Australian desert, and the water would be used in irrigation. Another of Pedrick’s inventions was a radio-controlled golf ball. A golfer could change the speed and direction of the golf ball by small flaps, controlled by computer chips.
Using radio waves, the golfer could also find lost golf balls. Arthur Pedrick had thousands of bizarre ideas for inventions, most of which were never built.
Though many of Pedrick’s inventions were never developed, a lot of other strange ideas were. In 1989, a company designed and sold a theft-prevention device for expensive cars. As part of this device, several tubes were attached to the bottom of a car. If someone tried to steal the car, super hot flames would come out of the tubes and burn the car thief. Some people who were not thieves, however, were seriously injured, when they accidentally set off the device by walking past the car. Other strange inventions include underwear for dogs and pens with drinkable ink. The underwear keeps dogs from making a mess when they go out for a walk. Also, if you are ever thirsty during a test, a pen with drinkable ink would be very handy!
If you have an idea that seems a little out in left field, don’t let that stop you from trying it. You’ll be in good company.
Questions 1-5:Read the passage carefully and then complete each space in the summary, using a maximum of three words from the passage.
Summary: Most inventions are for useful things that help people in everyday life. Some inventions, however, are just weird ideas that run counter to 1 . Some of the world’s weirdest ideas for inventions came from a man named Arthur Pedrick. Pedrick’s inventions included 2 that carried ice from Antarctica to Australia and radio wave-controlled 3 . Not all weird inventions came from Pedrick, however. Every year many people design products that could be considered unusual. Things like 4 made for dogs and pens 5 are good examples.
Most people have no idea of the hard work and worry that gointothe collecting of those fascinating birds and animals that they pay to see in the zoo.One of the questions that is always asked of me is 1 I became an animal collector in the first 2.The answer is that I have always been interested in animals and zoos.According to my parents, the first word I was able to say with any 3 was not the conventional “mamma” or “daddy”,4 the word “zoo”, which I would 5 over and over again with a shrill 6 until someone, ingroupsto 7 me up, would take me to the zoo.When I 8 a little older, we lived in Greece and I had a great 9 of pets, ranging from owls to seahorses, and I spent all my spare time 10 the countryside in search of fresh specimens to 11 to my collection of pets.12 on I went for a year to the City Zoo, as a student 13 , to get experience of the large animals, such as lions, bears, bison and ostriches,14 were not easy to keep at home.When I left, I 15 had enough money of my own to be able to 16 my first trip and I have been going 17 ever since then.Though a collector's job is not an easy one and is full of 18 ,it is certainly a job which will appeal 19 all those who love animals and 20. 请在4处填上正确答案()
Most people have no idea of the hard work and worry that gointothe collecting of those fascinating birds and animals that they pay to see in the zoo.One of the questions that is always asked of me is 1 I became an animal collector in the first 2.The answer is that I have always been interested in animals and zoos.According to my parents, the first word I was able to say with any 3 was not the conventional “mamma” or “daddy”,4 the word “zoo”, which I would 5 over and over again with a shrill 6 until someone, ingroupsto 7 me up, would take me to the zoo.When I 8 a little older, we lived in Greece and I had a great 9 of pets, ranging from owls to seahorses, and I spent all my spare time 10 the countryside in search of fresh specimens to 11 to my collection of pets.12 on I went for a year to the City Zoo, as a student 13 , to get experience of the large animals, such as lions, bears, bison and ostriches,14 were not easy to keep at home.When I left, I 15 had enough money of my own to be able to 16 my first trip and I have been going 17 ever since then.Though a collector's job is not an easy one and is full of 18 ,it is certainly a job which will appeal 19 all those who love animals and 20. 请在9处填上正确答案()
Most people have no idea of the hard work and worry that gointothe collecting of those fascinating birds and animals that they pay to see in the zoo.One of the questions that is always asked of me is 1 I became an animal collector in the first 2.The answer is that I have always been interested in animals and zoos.According to my parents, the first word I was able to say with any 3 was not the conventional “mamma” or “daddy”,4 the word “zoo”, which I would 5 over and over again with a shrill 6 until someone, ingroupsto 7 me up, would take me to the zoo.When I 8 a little older, we lived in Greece and I had a great 9 of pets, ranging from owls to seahorses, and I spent all my spare time 10 the countryside in search of fresh specimens to 11 to my collection of pets.12 on I went for a year to the City Zoo, as a student 13 , to get experience of the large animals, such as lions, bears, bison and ostriches,14 were not easy to keep at home.When I left, I 15 had enough money of my own to be able to 16 my first trip and I have been going 17 ever since then.Though a collector's job is not an easy one and is full of 18 ,it is certainly a job which will appeal 19 all those who love animals and 20. 请在6处填上正确答案()
What is the speaker’s opinion of the idea that electronic instruments will destroy classical music?
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Which of the following best expresses the main idea of the passage?