In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
Which of the following is NOT a type of barrier to precipitation: physical, equatorial, or atmospheric?, Context: The primary source of rain in the Sahara is the equatorial low a continuous belt of low-pressure systems near the equator which bring the brief, short and irregular rainy season to the Sahel and the southern Sahara. The Sahara doesn't lack precipitation because of a lack of moisture, but due to the lack of a precipitation-generating mechanism. Rainfall in this giant desert has to overcome the physical and atmospheric barriers that normally prevent the production of precipitation. The harsh climate of the Sahara is characterized by extremely low, unreliable, highly erratic rainfall; extremely high sunshine duration values; high temperatures year-round; negligible rates of relative humidity, a significant diurnal temperature variation and extremely high levels of potential evaporation which are the highest recorded worldwide.
Answer:
equatorial