Direction: Read the following passage and answer the given questions. A desert…
2017
Direction: Read the following passage and answer the given questions.
A desert is basically a wilderness or a wasteland. There is little moisture and poor soil such as sand gravel or rock. There are few plants to offer shade. Deserts can be described as harsh places. Many are burning hot by day and cold by night.
Every continent has deserts. Much of the western United States is a desert. A desert region called The Outback covers Central Australia. The southern tip of South America is largely desert. Northern Africa is covered by the Sahara, a desert as big as the mainland United States. The Arabian Peninsula, between the Persian Gulf and the Red Sea, is almost entirely desert. A large part of central Asia, from China to the Caspian Sea, is mostly desert. Deserts cover 1/8 of our planet.
The popular belief is that a desert is dry, hot, waterless and without shelter. But this is not entirely correct. For those who have studied it, the desert can be a beautiful place. It is home to a variety of people, animals and plants that have learnt to live under hot and dry conditions. A desert is not always a flat, unchanging wasteland of dry sand. It may have mountains and hills. It may have an oasis, big or small. An oasis is like a green island in the middle of a desert where a spring of a well gives plants and trees a better chance to grow.
All living things need water in order to survive. The few plants and animals that live in deserts have developed the ability to require less water than most plants and animals. Desert plants have adapted to heat and dryness of the desert. Plants such as cacti have special means of storing and conserving water. They often have few or no leaves. Some plants have gotten used to arid environments by growing extremely long roots, allowing them to acquire moisture at or by the water table.
The desert animals also have found a way to solve the heat and water problems the dessert environment creates. Camels can drink a lot of water at one time. They can live without water for days together. The reason is they sweat very little. We sweat because we must keep our body temperature constant. They sweat when it gets hot, and this cools the body. Camels can stand a high body temperature. They don't need to sweat and can therefore retain the water they drink for long periods of time.
Why has an oasis been called 'green' island?
- A.
It is in the middle of a vast desert.
- B.
The sand here is conducive for the vegetation.
- C.
It is surrounded by green hills and mountains.
- D.
It has a source of water that supports vegetation.
Show answer & explanation
Correct answer: D
In a “why is X called Y” reading-comprehension question, the task is to find the sentence in the passage that explicitly gives the reason for the label, then match that reason — not a nearby but unrelated detail — to the options; the answer is a literal fact stated in the text, not something inferred or brought in from outside knowledge.
The passage states: “An oasis is like a green island in the middle of a desert where a spring or a well gives plants and trees a better chance to grow.” This sentence gives the reason directly: a spring or well (a source of water) lets plants and trees grow, and that vegetation is what makes the oasis look “green” against the surrounding desert.
It is in the middle of a vast desert: the passage does place an oasis within a desert, but that is a statement of location, not a reason for the 'green' label.
The sand here is conducive for the vegetation: the passage instead describes desert soil as poor ('little moisture and poor soil such as sand, gravel or rock'), so it never attributes plant growth to the sand.
It is surrounded by green hills and mountains: the passage's remark that deserts 'may have mountains and hills' is a general statement about desert terrain, not a description of an oasis's surroundings.
So the reason the passage gives for the 'green island' label is the presence of a water source — a spring or well — that supports the vegetation growing there, matching the option about a source of water supporting vegetation.