Question

Read the paragraph and choose a sentence that describes it best. When most people imagine an archetypal desert landscape—with its relentless sun, rippling sand and hidden oases—they often picture the Sahara. But 11,000 years ago, what we know today as the world’s largest hot desert would’ve been unrecognizable. The now-dessicated northern strip of Africa was once green and alive, pocked with lakes, rivers, grasslands and even forests. So where did all that water go? The Sahara has long been subject to periodic bouts of humidity and aridity. These fluctuations are caused by slight wobbles in the tilt of the Earth’s orbital axis, which in turn changes the angle at which solar radiation penetrates the atmosphere. At repeated intervals throughout Earth’s history, there’s been more energy pouring in from the sun during the West African monsoon season, and during those times—known as African Humid Periods—much more rain comes down over north Africa. a) Sahara will turn green again in some time, and humans cannot influence this b) Changes in the Earth’s axis cause the changes of Sahara climate c) The deserts are produced by the changes of the Earth’s axis d) The water reducing caused Sahara to become

Answer 1

The sentence that best describes the paragraph is:

b) Changes in the Earth’s axis cause the changes of Sahara climate.

1. The paragraph discusses the Sahara desert's transformation from a green and alive landscape to its current arid state.

2. It explains that the Sahara's climate fluctuations are caused by changes in the Earth's axis.

3. These changes in the tilt of the Earth's orbital axis affect the angle at which solar radiation penetrates the atmosphere.

4. As a result, there are periods known as African Humid Periods when more rain falls over North Africa, leading to a greener Sahara.

5. The paragraph emphasizes the connection between changes in the Earth's axis and the climate changes in the Sahara.

In summary, the paragraph highlights how changes in the Earth's axis are responsible for the climate changes in the Sahara desert, causing it to transition between periods of aridity and humidity.