Question

Directions: After reading the passage below, fill in the blanks to make the passage coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; for the other blanks, use one word that best fits each blank.

How Do Avalanches Happen

If you’re ever skiing in the mountains, you’ll want to be aware of avalanches. An avalanche is a sudden flow of snow down a slope, such as a mountain. The amount of snow in an avalanche 1. (vary) based on many things, but it can be such a huge amount that it can bury the bottom of a slope in dozens of feet of snow.

Avalanches 2. be caused by natural things. For example, new snow or rain can cause built-up snow to loosen and fall down the side of a mountain. Artificial triggers（诱发因素）can also cause avalanches. For example, snowmobiles, skiers, and explosives 3. (know) to lead to avalanches.

Avalanches  usually occur  during the  winter  and spring, 4. snowfall  is  greatest.  As they are dangerous to any living beings in their path, avalanches have destroyed forests, roads, railroads and even entire towns. Warning signs exist that allow experts to predict -- and often prevent -- avalanches from 5.

  (occur). When over a foot of fresh snow falls, experts know to be on the lookout for avalanches. Explosives can be used in places 6. massive snow buildups to trigger much smaller avalanches that don’t   pose a danger to persons or property.

When deadly avalanches do occur, the moving snow can quickly reach over 80 miles per hour. Skiers caught in such avalanches can be buried under dozens of feet of snow. 7. it’s  possible to dig out  of such avalanches, not all are able to escape.

If you get tossed about by an avalanche and find yourself 8. (bury) under many feet of snow, you might not have a true sense of which way is up and which way is down. Some avalanche victims have tried to dig their way out, only to find that they were upside down and digging 9. farther under the snow rather than to the top!

Experts suggest that people caught in an avalanche try to dig around  you 10. (create) a space for air, so you can breathe more easily. Then, do your best to figure out which way is up and dig in that direction to reach the surface and signal rescuers.

Answer

1.will vary / varies

2.can

3.have been known / are known

4.when

5.occurring

6.with

7.While/Though/Although

8.buried

9.themselves

10.to create

【解析】

本文是一篇说明文，介绍了雪崩是怎样发生的及如何在雪崩中逃生。

1.考查时态。句意：雪崩中的雪量因许多因素而不同，但雪量可能非常大，以至于可以将斜坡的底部埋在几十英尺深的雪中。陈述的是客观事实，用一般现在时，主语是The amount of snow，谓语动词用第三人称单数，也可用一般将来时，表示“会、将会”，故填will vary / varies。

2.考查情态动词。句意：雪崩可能是自然因素造成的。空后是动词原形，此处需要填情态动词，根据“Artificial triggers（诱发因素）can also cause avalanches.”可知此处表示“能、可能”，故填can。

3.考查时态语态。句意：例如，众所周知，雪地车、滑雪者和炸药会导致雪崩。snowmobiles, skiers, and explosives 与know之间是被动关系，陈述的是客观事实，用一般现在时的被动语态，也可理解成过去的动作对现在造成的影响，用现在完成时的被动语态，主语是复数，谓语动词也用复数，故填have been known / are known。

4.考查非限定性定语从句。句意：雪崩通常发生在冬季和春季，那时降雪量最大。此处为非限定性定语从句，先行词为the winter and spring，指时间，关系词在从句中做时间状语，故填when。

5.考查非谓语动词。句意：预警信号的存在，使专家能够预测——并经常防止雪崩的发生。prevent sth from doing表示“防止某事发生”，故填occurring。

6.考查介词。句意：在有大量积雪的地方可以使用炸药来引发较小的雪崩，不会对人或财产造成危险。分析句子结构可知此处填介词，根据句意可知此处表示“具有”，故填with。

7.考查让步状语从句。句意：虽然从雪崩中逃生是可能的，但并不是所有人都能逃脱。根据句意可知前后是让步关系，此处表示“尽管、虽然”，故填While/Though/Although。

8.考查非谓语动词。句意：如果你被雪崩抛来抛去，发现自己被埋在许多英尺厚的雪下，你可能无法真正知道哪条路是向上的，哪条路是向下的。此处为“find+宾语+宾补”结构，yourself与burry之间是逻辑上的动宾关系，表示被动，用过去分词做宾语补足语，故填buried。

9.考查代词。句意：一些雪崩受害者试图挖出他们的出路，却发现他们是颠倒的，在雪下挖得更深，而不是在顶部。dig oneself +介词（短语）表示“挖洞使自己……”，根据“they”可知此处指“他们自己”，故填themselves。

10.考查非谓语动词。句意：专家建议，被雪崩困住的人尽量在你周围挖掘，为空气创造一个空间，这样你就能更轻松地呼吸。此处表示目的，用不定式做目的状语，故填to create。