The phrase “opting out” in Paragraph 3 means ____.

Dogs are extremely useful as companions for blind people. When a dog has been properly trained, he will always lead his blind master in the right direction and keep him out of danger. For example, seeing—eye dogs learn never to cross a busy road when cars are coming, even if their masters command them to do so.

Horses that are used for guard or police duty must learn never to be frightened of noises, traffic, and other disturbance. (46. Racing horses are able to run much faster than other horses, but they are also quite high strung. Therefore, it is necessary for people who train them to be very patient and understanding.)

Pigeons have a natural instinct to return home, even if they are very far away and the trip is hard or dangerous. (47. Men utilize this homing instinct to send messages on small pieces of paper that are fastened to the pigeon’s back or legs. Pigeons have been known to fly as fast as 75 miles an hour and to cover distances of 500 to 600 miles.) These homing pigeons begin their training when they are about four weeks old. After a few weeks they can begin flying and carrying messages. If all goes well, their flying career lasts about four years.

Animals can learn to do many things that, while not necessarily useful, are very amusing to watch. (48. In circuses, animals are taught to do the tricks that are most compatible with their physical and temperamental make—up. Lions and tigers can be taught to leap and spring gracefully when told to do so, or to stay in place on command.) Elephants learn to walk in line, to stand on their hind legs, to lie on their sides, and to stand on their head. They can also learn to dance.

Another trainer had an elephant and a tiger, who after many weeks of living in the same cage, became accustomed to each other. Then the tiger was taught to jump on the elephant’s back. (49.Both animals become so interested in the act (as well as the praise and food they received after the act) that they forgot they were natural enemies.) Later a lion was added to the act. This also took a lot of training. However, when the three animals grew accustomed to each other they made a most successful circus act.

Cinema and television use trained animals too. Some animals, such as skunks and foxes, are easy to film. All you have to do is to make a trail in front of the camera by dragging something that smells good to the animals over the ground. Big animals, such as lions and tigers, can be photographed as they bound happily back to their families and dinner. (50. If a movie actor is nearby, the well—trained animal will pay no attention to him. However, the audience may imagine that the actor escaped a terrible death by the skin of his teeth.)

Paragraph Ten

Einstein rebelled against rote learning, and that attitude helped make him the genius that he was. Likewise, our success as a nation will be determined not just by how well our schools teach the multiplication and periodic tables but by how well they promote imagination and creativity.

What should be p____ in school?

Paragraph Nine

Convenience friends are convenient indeed. They’ll lend us their cups and silverware for a party. They’ll drive our kids to soccer when we’re sick. They’ll take us to pick up our car when we need a lift to the garage. They’ll even take our cats when we go on vacation.

As we will for them.B____ of convenience friends.

Paragraph Eight

We are successful because we can form long—lasting relationships with many others in diverse and flexible ways, and that this, combined with our native intelligence, explains why Homo sapiens came to dominate the planet. In every way from teaching our young to the industrial division of labor we are a massively co—operative species that relies on larger and more diverse networks of relationships than any other species.

I____ of relationships.

Paragraph Five

With their normal summer diet of greens and berries shriveled by summer heat or drought in many spots nationwide, hungry bears are rummaging through garbage, ripping through screens and crawling into cars in search of sustenance.

Hungry bears s____ for food.

Paragraph Six

Everyone knows that a placebo — a fake medication or sham procedure, typically used as a control in a medical trial — can nonetheless have a positive effect, relieving real symptoms like pain, bloating or a depressed mood. The placebo effect is a result of the patient’s expectation that the treatment will help.

F____ of a placebo.

Paragraph Seven

Standardized teaching an be done by mediocre teachers using scripted lessons. Excellent teaching requires well—honed judgments about individual students based on observation, information from a robust assessment program, and a great deal of knowledge and informed intuition about young people.

Q____ of excellent teaching.

Paragraph Three

When infants 18 months old see an unrelated adult whose hands are full and who needs assistance opening a door or picking up a dropped clothespin, they will immediately help. The helping behavior seems to be innate because it appears so early and before many parents start teaching children the rules of polite behavior.

Human beings may be b____ with the urge to help.

Paragraph Two

A sand castle is made of a network of sand grains glued together by very thin bridges of water. Without any water, sand flows; a perfectly dry sand castle would collapse into a heap. Too much water, on the other hand, creates sand soup. But embedded in a matrix of water molecules, sand particles stay in place, somewhat like molecules in solid substances.

Proper amount of water is the key to b____ sand castles.

Paragraph Four

People across the northern hemisphere are facing the fact that a warming planet doesn’t get rid of winter. On Monday the heaviest snow on record plastered Seoul. In coming days, the central US will experience its most brutal cold wave in 10 to 20 years. And most of Western Europe will be encased in a deep freeze by this weekend.

Winter is still c____.