Question

this event chain shows the events of the failed apollo 13 mission to the moon. april 11, 1970: apollo 13 launches. oxygen tank no. 2 explodes. all three fuel cells fail. oxygen tank no. 1 is damaged. the moon mission is aborted. nonessential systems, like heat, are turned off. the crew becomes sick and dehydrated. temperatures drop close to freezing. april 17, 1970: the crew lands safely on earth. based on the event chain, which of these events happened before the others? temperatures approached freezing. oxygen tank no. 2 was damaged. oxygen tank no. 1 was damaged. the mission was aborted.

Explanation:

Looking at the event chain, we can see the order of events. The first event after the launch is the explosion of Oxygen tank no. 2. Then Oxygen tank no. 1 is damaged. After that, all three fuel cells fail, leading to the mission being aborted. Non - essential systems (including heat) are turned off, causing temperatures to drop close to freezing.

Answer:

Oxygen tank no. 2 was damaged.