instruction:
In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
question:
San Diego (CNN) Twenty-five years ago, Paula Claussen's friend invited her to make the short trip from her home in San Diego, California, across the border to Tijuana, Mexico, to donate clothing to people in need. Claussen didn't expect that day to change the course of her life. The drive took less than an hour, but when they arrived at their destination -- a shantytown on the outskirts of Tijuana -- Claussen couldn't believe her eyes. "I was shocked by the conditions that I saw down there," she said. Families with young children were living in ramshackle homes: The dirt floors turned to mud when it rained. The walls had gaps, allowing tarantulas, rattlesnakes and rats to invade. Many roofs were merely old tarps with holes in them.Paula Claussen visited Tijuana, Mexico, to donate clothing 25 years agoThe poverty she saw inspired her to come back and build better homes for residentsProject Mercy houses replace shacks that often have dirt floors and lack basic amenities 
 Question:The nonprofit has constructed more than 1,250 free homes for people living in _'s most desperate communities.
answer:
Tijuana


question:
What does it sound like to land on the surface of Saturn’s moon Titan or fly past the Martian moon Phobos? Thanks to the European Space Agency you can listen to these sounds - and more - recreated by processing data from various spacecraft. The amazing collection of clips include some that have been artificially amplified to be audible to humans, and others that are simply as they originally sounded. The recent launch of a Soyuz rocket that took two European satellites into orbit can also be heard in one amazing clip. It took off from French Guiana at 9.46pm GMT on Friday 27 March (pictured), carrying two satellites that will expand Europe’s Galileo systemThe European Space Agency's Soundcloud page reveals clips of spaceThey include the noises heard as a probe landed on Titan in 2005'Singing' from comet 67P as recorded by Rosetta is also heardAnd you can also listen to a variety of rocket launches 
 Question:Scientists at _ are hoping that the probe will wake up in the coming weeks as sunlight recharges its batteries, letting them perform more key science on the surface.
answer:
European Space Agency


question:
Corning, California (CNN) Seven-year-old Gage did what the teachers said. He knew the drill. A whistle blows. You go into lockdown. Go inside. Get real quiet. Hide under the desk. A gunman had emerged outside Rancho Tehama Elementary School in Northern California. He fired at the building. He got closer, and fired some more. Gage said he heard his class door being jostled. It was the bad man outside. He was trying to get in. The locked door kept the gunman out Tuesday morning, and Gage survived along with his classmates and teachers. The gunman was a man Gage knew and feared: his neighbor Kevin Jason Neal.Boy survived along with his classmates and teachers at schoolGunman shot and killed boy's father and grandmother before heading to the school 
 Question:_ soon found out the gunman who had just caused pain and havoc at his school had also destroyed his home life.
answer:

Gage