Q:Read the following article and select the best answer. Article: I don't have too many memories of my father because he was so sick in the last years of his life. But there aresome that I am often reminded of and which may have developed my love ofscience. When I was small, I was somewhatafraid of lightning and thunder . My father explained it. The explanation wasin words that a child could understand but was basically correct. I gained a betterunderstanding and learnt something from him. What he said was that there was electricity in the cloudsand it traveled to the ground like a spark . When it traveled through the air, it made the air so hot that it burned. Then there was nothing where the air had been and the air all around rushed in to fill the space. Saying this, he clapped his hands together very loudly, pretending to be the air rushing in, and said that makes the thunder. When I hear thunder, I can still hear that clap clearly. He also explained why a cloudy winter night was warmer than a clear one. When there were clouds, they were like blankets which kept the earth and us warm. He said that if there were no clouds, we had no blankets and were _ to the universe. Our warmth was going toheat the whole universe. Even today, I still feel on the edge of space on a very clear night. I am sure there were many other lessons that Itook but no longer remember most of them now. What I didlearn, in general, was that there were explanations and that the more I understood them, the more comfortable the world was to live in. I was not taught that there were mysteries but that there was understanding if you looked for it. This may be why I have always takenaninterest in science. Question: The writer's father explained that there was thunder because _ and made it. - his hands clapped loudly - rushing air filled the space - electricity traveled through the air - thick clouds knocked into each other
A:
rushing air filled the space