In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

[Q]: Article: Campers Gene and Marie Marsden took pride in being good citizens when in the wild. While driving miles to the Green River Lakes area, they taught their children what they had learned in the bear safety handbook put out by the Bridger-Teton Forest Service. Mr. and Mrs. Marsden did their best to keep a tidy camp. As the handbook had said to hang all food at least ten feet off the ground and four feet out from the trees, they did that and locked their food in their trailer at night. It was already dark when they went to bed, but they _ the campsite with flashlights, making sure nothing was left out. Following the bear book's advice, they slept a hundred yards from where they cooked their food, and kept the car near their tents, separated from the trailer, which they left up at the other camp. The Marsdens liked having their dog Spike on guard. But on the first night, Spike would not stop barking. When Marie Marsden pulled the tent open and shone her flashlight, she saw a young bear. They all piled into the car and drove quickly down the path, calling out of the window to Spike and abandoning the trailer. They drove to a pay phone and called a Fish and Game Department guard, who identified the bear by the white ring of the fur the Marsdens had seen around his neck. The authorities informed the Marsdens that the bear was a young male that they'd been keeping an eye on. The next morning, the Marsdens heard helicopters circling over the mountain and wondered if it might have something to do with the bear. After spending the night in the public campground, they drove back to their site. Wandering the area in search of clues, Marie came to a stop below a tall tree. She slapped her head and shouted, "Oh no!" "What is it?" Gene asked. Marie pointed at the ground where Spike's dog food bowl lay upside down. A week after their return home, the Marsdens read the headline in their local paper. "Bear Killed in Wind Rivers." According to the article, the Fish and Game Department had shot the young bear because, having been rewarded for invading a human campsite, it would likely to do so again. The Marsdens knew they had been lucky in the encounter, yet much to their shame and sadness, they also knew that the bear had not.
Answer: They did what the bear safety handbook had said.
[A]: What do we know about the Marsdens?

[Q]: Article: When Juliet was a child, she often went to the city park and played with her friends. On a sunny morning, when Juliet came to the park with her mum, she looked around and felt very unhappy. "What's the matter, dear?" asked her mum. Juliet replied, "Mum, there's so much trash on the ground." Juliet's mum looked around. There was paper, boxes and glass bottles everywhere. "What can we do?" asked Juliet. "I'm sure you will think of something," said her mum. As soon as Juliet and her mum went home, Juliet painted a picture of the park and wrote a sign in large black letters at the top of the picture. The sign read "PLEASE KEEP OUR PARK CLEAN". Later, she took plenty of bags and went back to the park with her mum. Juliet put up her picture on a big trash can . "Will you help me pick up the trash, Mum?" Juliet said as she handed her mum a bag. "I sure will," replied her mum. The children at the park ran over to see what was going on. Juliet handed them each a bag. "Let's clean this place up," said Juliet. Then they began to pick up the trash, talking and laughing. Soon all the bags were full. "We need to come back another day. There's still some trash on the ground, but the park looks much better," said Juliet. Her mum said, "So it does. _ "
Answer: Because there was too much trash at the park.
[A]: Why was Juliet sad?

[Q]: Article: Bats are impressive creatures. They are known to carry dangerous diseases like SARS without getting sick. So researchers wanted to know: How do bats fight off so many deadly diseases? Learning their secret could help doctors better treat humans who have these diseases, therefore saving millions of lives. To solve this problem, a team of researchers from Australia and China analyzed bat DNA. The scientists studied two kinds of bats--the Australian megabat, known as the flying fox, and the Chinese microbat. The scientists then arranged the bat genome in order by comparing their DNA. The researchers now think that the special immunity to illness that bats have may be connected to their ability to fly. Bats are the only mammals that can truly fly. Flying uses up a lot of energy. The energy burned for flying produces something in the animal called free radicals . Free radicals can damage DNA and lead to diseases such as cancer. However, bats are not affected by free radicals produced during flight. The reason is that bats carry special genes to repair any damaged DNA. Scientists think that because bats fly and produce free radicals, they've evolved to carry genes that shaped their special immune system. "We're thinking that the evolution of flight led to a sort of effect, influencing not only the immune system but also things like aging and cancer," says Chris Cowled, of the Australian Animal Health Laboratory. "We think we've really found something special." Researchers believe that this discovery might one day be key to helping humans fight diseases such as cancer that attack the immune system and damage DNA.
Answer: Researchers studied bats to help save people.
[A]:
What's true about bats according to the passage?