Read the text and answer the questions.

As computer technology has improved, today's online environments have become more complex and realistic. One website that has attracted over six million Internet users is Second Life.

Second Life is a three-dimensional (3-D) online world where people work, shop, sell and trade items, meet others, go to concerts, and much more. Users, who are called "residents," create their own characters, or "avatars." They use their avatars to explore Second Life's virtual world.

Just like any country, Second Life has its own economy. Using a credit card, users can buy "Linden Dollars," the official currency of Second Life. With Linden Dollars, they can buy land or even an entire island where they can build and decorate their own house, start a garden, or even set up their own store. Land is treated as a valuable commodity in Second Life. Residents can choose to rent or sell their land to other users, and they can earn real money from these transactions. Some users have reported making tens of thousands of dollars from selling Second Life real estate.

When residents want to be social (and most of them do) they can use their avatars to interact with others. There are games, shopping malls, clubs, and many kinds of stores available to residents. Avatars can also attend conferences, art shows, and concerts. Real rock bands such as the British pop group Duran Duran, have even given live concerts on Second Life. With so many opportunities for interesting things to do and see, it's easy to see why so many users spend so much time on the site.

Second Life offers users a quick and easy escape from the real world. Many residents see this as one of the main benefits of using the site. Spending time on Second Life allows them to escape the stresses and problems of their daily lives. If a user is having a stressful day at work, she can visit a beautiful island, go skiing, or even fly to another planet during her lunch break. If she is tired at the end of a long day, she can go to a classical music concert while dinner is cooking and never leave home. Users can even visit other planets to help them forget their "first-life" problems for a little while.

In addition to escaping the stress of their daily lives, users can also escape who they are in the real world and live out their fantasies. For example, residents can change their occupations, physical appearance, and even their nationalities. A doctor from the United States can be a Brazilian musician on Second Life, or a banker can choose to be an Olympic basketball player. Basically, Second Life lets users live in a world without limitations. This is very exciting to many people.

Although Second Life started as a way for people to escape the real world, it has become more and more like the real world in many ways. Now on Second Life, some countries have virtual embassies, businesses have meetings in virtual rooms, and universities have places where students can view the campus and take classes. Today, Second Life allows users to experience both fantasy and reality in the same place.

When the rock comes out of the hole, it is called lava, and it is so hot it is (5) ___________.