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.

Article: In the past, friendships were greatly limited by time, space and attention; increasing home and workplace mobility has made it even harder to keep social relations over time. Through a combination of user controls, new technologies and changing standards of social behavior, Facebook is freeing us from these limitations, making friendships more accessible, pleasant and diverse than ever before. First, Facebook allows you to find and rediscover friends and then reminds you of these connections, so that you are less likely to fall out of touch with the long-lost school friend, or the family member in a different country. 'Second, Facebook creates an environment that allows you to interact easily with others : you can share your photos,videos,links and thoughts with your friends, and respond to what they share in turn. Third, Facebook's unique technical system helps you to discover your friends,most valuable stories. These technologies allow people to keep and enrich friendships that they might otherwise have been unable to keep. The effect of this is very great. A recent study by Keith Hampton for the Pew Internet and American Life Project discovered that users of social networking websites have larger, more diverse social circles, online and offline. This outcome comes at no cost to one's closest relationships, which are kept in person and over the phone. Instead, the hour that the average user spends each day socializing on Facebook comes at the expense of less social activities, such as the three or so hours a day the average person spends watching television. Time may limit our ability to keep social ties, but our desire for social communication is limitless. Just as boats have allowed us to cross oceans and vehicles have allowed us to move mountains, Facebook is a tool that allows us to stay more deeply connected with a larger and more diverse set of friends.
Answer: Change the behavior towards your friends.
What can you do with the help of Facebook according to the text?

Article: Women are friendly. But men are more competitive. Why? Researchers have found it's all down to the hormone oxytocin . Although known as the love hormone, it affects the sexes differently. "Women tend to be social in their behavior. They often share with others. But men tend to be competitive. They are trying to improve their social status," said Professor Ryan. Generally, people believe that the hormone exytocin is let out in our body in various social situations and our body creates a large amount of it during positive social interaction such as falling in love or giving birth. But in a previous experiment Professor Ryan found that the hormone is also let out in our body during negative social interactions such as envy. Further researches showed that in men the hormone oxytocin improves the ability to recognize competitive relationships, but in women it raises the ability to recognize friendship. Professor Ryan's recent experiment used 62 men and women aged 20 to 37. Half of the participants received oxytocin. The other half received placebo . [( )] [( :Love my Dog.)] After a week, the two groups switched with participants. They went through the same procedure with the other material. Following each treatment, they were shown some video pictures with different social interactions. Then they were asked to analyze the relationships by answering some questions. The questions were about telling friendship from competition. And their answers should be based on gestures, body language and facial expressions. The results indicated that, after treatment with oxytocin, men's ability to correctly recognize competitive relationships improved, but in women it was the ability to correctly recognize friendship that got better. Professor Ryan thus concluded: "Our experiment proves that the hormone oxytocin can raise people's abilities to better distinguish different social interactions. And the behavior differences between men and women are caused by biological factor that are mainly hormonal."
Answer: Oxytocin.
What causes men and women to behave differently according to the text?

Article: Teen models are not difficult to find. An online agency features both models young as well as older. Those who are looking for child models to show off their products and make them look better can find what they are looking for by hiring children models from these online modeling agencies. This is less expensive than trying to go through large modeling agencies that often cost thousands of dollars for the client . Many of those who are selling children's products and have websites for parents and children are looking for teen models. As a result, there is more of a need for young models to participate in the field of modeling. The best way for clients to hire models that will not end up costing them a fortune is to use an online modeling site. An online modeling site will have portfolios of models young as well as old. Someone who is looking for teen models can find a variety of different children when they take a look at these sites. Online teen models usually work for less money than offline models, although they are still paid well enough to make it worth their while to model. Clients who are looking for young models can go on an online modeling agency to look for portfolios of the teens that they will want to use in their advertising campaigns. Parents or guardians must agree to the modeling offers and the agency will act as a go-between for both the teen models as well as the clients who are looking for young models. Clients can look through portfolios for the young models and get the ones that are right for what they are looking for to advertise for them. It is now affordable for anyone to hire teen models when using an online modeling agency site. Parents of young models can also use these sites to get their teens a chance to get a head start in the world of modeling.
Answer: They can offer teen models that cost clients less money.
What is the main advantage of online modeling agencies?