In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
One 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.
Solution is here: Russian Revolution
Explanation: This is a good example, and the Russian Revolution is the first event mentioned.

Now, solve this: In most animals such as mammals, what is used to transport oxygen or hormones throughout the body?, Context: These were fighting words to be coming from a country that once insisted Europe needed Turkey and was willing to spill blood over it. For his authority Miller invokes the people, citing the "collective wisdom" of Europe, and introducing a concept to arise many times in the decades to follow under chilling circumstances:
Solution:
blood