In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.

Q: Article: If you give something to someone for free, will that person value it and use it? Development experts have debated this question for decades. Some think the act of paying causes people to value something and use it more. Selling necessary health treatments, others argue, may deny them to the people who need them the most. Consider, for example, chemically treated bed nets, which kill mosquitoes anti protect people against malaria while they are sleeping. William Easterly, an economist at New York University, believes this is one example of development having gone wrong. In a recent book, Professor Easterly suggests bed nets given free in Africa are often used for the wrong purpose. Yet, the World Health Organization (WHO) recommends bed nets be given out free and used by whole communities. The success of a large free bed net campaign in Kenya led the WHO to announce this recommendation This debate will likely influence social programs in the developing world. Many non-governmental organizations support the creation of self-supporting programs in poor countries. Goods and services are sold for a price to help these programs survive. According to Rachel Glenerster, who runs a research lab doing development and poverty studies at the Massachusetts Institute of Technology, her several studies have proven that small price changes have a big influence on the number of people who use a product. A price change will reduce the total amount of use of the product as well, she says. She has also found no evidence that the very act of paying for something changes how people use it. As for a particular product among special populations, some development experts argue that pricing is useful. When it comes to bed nets, Miss Glenerster says research shows no evidence of this. People are just as likely to use a bed net whether they paid for it or not.
Answer: a popular way to help the poor

A: The debate among experts focuses on _ .
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Q: Article: At night, bats fly through the air, catching hundreds of insects and other small animals. But during the day, they hardly move at all. Instead, bats pass the time hanging upside down from a secret spot. There are a couple of reasons why bats rest this way. First of all, it puts them in a position for takeoff. Unlike birds, bats can't fly into the air from the ground. Their wings don't produce enough lift to take off from a dead stop, and their hind legs are so small and underdeveloped that they can't run to build up the necessary takeoff speed. Instead, they use their front claws to climb to a high spot, and then fall into flight. During the hours when most enemies are active, bats gather where few animals would think to look and most can't reach. This allows them to disappear from the world until night comes again. There's also little competition for these resting spots, as other flying animals don't have the ability to hang upside down. Bats have a unique physiological adaptation that lets them hang around this way without using any energy. For you to hold your fist around an object tight, you contract several muscles in your arm, which are connected to your fingers by tendons ;as one muscle contracts, it pulls a tendon, which pulls one of your fingers closed. A bat's talons close in the same way, except that their tendons are connected only to the upper body, not to a muscle. To hang upside down, a bat pulls its claws open with other muscles. To get the talons to take hold of the surface, the bat simply lets its body relax. The weight of the upper body pulls down on the tendons connected to the talons, causing them to hold tight. Therefore, the bat doesn't have to do anything to hang upside down.
Answer: they can't start to fly from the ground directly

A: Bats hang upside down because _ .
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Q: Article: Around the world there are some festivals that for some of us may sound _ . In England they celebrate the rolling cheese race, which occurs every year during the last Monday in May. This festival's characteristic is a contest where an official rolls cheese down a steep hill and festival- goers go chasing after it. The winner is the first one to reach and catch the cheese. Another festival celebrated in England is the world championship of grimaces . It is a celebration that dates back to 1297 and is celebrated during the month of September. The task is to perform the best grimace using anything you can to win. The worldwide championship of wife lifting is celebrated in Finland. The game is based on Viking traditions where a man should carry away his neighbor's wife. According to the rules, any woman above 17 is considered as a wife, so if you are within this age, take care while visiting this country during the month of July. Many of you have watched Pirates of the Caribbean and have known something about pirates. The 19thof September has been declared worldwide as the day to talk like a pirate. Plenty of people have celebrated it thanks to the publicity on the Internet. First staged in 1998, the Boryeong Mud Festival is an attraction that pulls more than a million visitors to the South Korean City. As you all know, the town is said to be rich in minerals, so there is no shortage of mud. Mud is trucked onto Daecheon Beach for tourists and locals to enjoy the festival to their best. The Monkey Buffet Festival is held in Thailand to develop tourism. It's an unusual feast held for about 600 monkeys. The Monkey Buffet Festival is held in honor of the Hindu gods Ram and Hanuman and involves 3,000 kilograms of vegetables and fruits being laid out for monkeys to stuff themselves.
Answer: be the first one to catch the cheese rolling downhill

A:
If a participant wants to win in the rolling cheese race, he / she should _ .
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