根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
Rock Climbing as Sport and Art
An estimated nine million people rock climb in the United States. Millions more take part in the activity around the world.   小题1: Others compete. Rock climbing can be dangerous. But there are many methods and protective devices that can increase a climber’s safety.
 小题2:   Climbers have to pull themselves straight up the face of very high rocks or walls. So they have to be strong enough to carry their own weight. And climbers sometimes have to hold on to rocks with only their fingers or toes.
There are several kinds of rock climbing. Traditional rock climbing is done outside. Climbers wear ropes and attach devices to the rocks as they climb many hundreds of meters up. They also connect their ropes to the devices.   小题3:  Sport climbing is similar. However, in those cases the protective devices are permanently placed in the rock. There is also indoor climbing. Rock walls made of wood or concrete have places for the climber’s hands and feet.
小题4:  People climb glaciers or frozen waterfalls instead of rocks. They use special equipment for the ice.
And then there is bouldering(巨石攀岩)— climbing rocks between three and seven meters high.   小题5:  Many climbers like bouldering because they can use less equipment. Climbers often need only special shoes and chalk. All climbers use chalk to keep their hands dry.
A.Ice climbing is exactly as it sounds.
B.Some do it just for personal satisfaction.
C.Some go climbing at weekends or in holidays.
D.It is a quicker and more intense(剧烈的;紧张的)kind of climbing.
E. If a climber slips, a rope can stop him from falling.
F. Climbing takes strength, control and good balance.
G. It is more challenging and dangerous, but also more fun.
下面文章中有5处(第61~65题)需要添加小标题。请从以下选项(A、B、C、D、E和F)中选出符合各段意思的小标题。选项中有一项是多余选项。
A. Control of Respiration
B. Basic tips for preserving cut flowers
C. Role of Respiration
D. Most Important Aspect of Flower Care
E. Need for Clean Water
F. Ways of Stopping Respiration
小题1: __________
While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long as possible. This may be done by keeping in mind a few simple facts. The key to keeping fresh cut flowers for a week or more without floral preservatives (which contain biocides that kill bacteria and fungus) is to keep the water fresh and the stems free of air pockets so they can continue to draw up water.
小题2:__________
An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations(康乃馨) retain their freshness eight times longer when kept at 12℃ than when kept at 26℃. Keeping freshly harvested flowers at the right temperatures is probably the most important aspect of flower care.
小题3:__________
Flowers are not intended by nature to live very long. Their biological purpose is simply to attract birds or insects, such as bees, for pollination (授粉). After that, they quickly dry up and die. The process by which flowers consume oxygen and produce carbon dioxide, called respiration (呼吸), generates the energy the flower needs to give the flower its shape and color. The making of seeds also depends on this energy. While all living things respire, flowers have a high level of respiration. A result of all this respiration is heat, and for flowers the level of heat relative to the mass of the flower is very high. Respiration also brings about the eventual death of the flower. Thus the greater the level of respiration, the sooner the flower dies.
小题4: __________
How, then, to control the rate at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature. We know that respiration produces heat, but the reverse is also true. Thus by maintaining low temperatures, respiration is reduced and the cut flower will age more slowly.
小题5: __________
Another vital factor in keeping cut flowers is the quality of the water in which they are placed. Flowers find it difficult to “drink” water that is dirty or otherwise polluted. Even when water looks and smells clean, it almost certainly contains harmful substances that can endanger the flowers. To rid the water of these unwanted substances, household chlorine bleach (含氯漂白剂) can be used in small quantities. It is recommended that 15 drops of chlorine bleach (at 4% solution) be added to each liter of water. The water and solution should also be replaced each day.
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