18．
In 2004，three young men went to a dinner party in San Francisco．Afterwards they wanted to share a video from the party with their friends．They wanted to send it over the Internet．But at the time，the process of sharing videos that way was difficult．Using e-mail did not work and the friends complained that there was no website to help them．So they created their own．They called their website YouTube．It made sharing videos easy，so the website soon became very popular．People watched 2，500million videos in the first six months!
Today，more than 70，000new videos go up on YouTube each day．People watch more than 1，000million videos a day．Many last no more than 10minutes．These videos show all kinds of things，from sleeping cats to earthquakes．Most of the filmmakers are not professionals（专业人士）．They are just everyday people making videos，and they use the website in many interesting ways．
First，many people use YouTube to entertain others．One example is Judson Laipply．He made a funny dance video and put it on YouTube in 2006．People watched the video more than 10million times in the first two weeks．Now people stop Judson on the street to ask，"Are you the dance guy on YouTube？"Some people have invited him to dance at their parties．A few women even asked to marry him．Judson wants to make more dance videos，and people look forward to seeing them．
Other people use YouTube to advertise a business．David Taub does this．He is a guitar teacher and he sells videos of guitar lessons on his own website．He wanted to increase his business，so he put short videos with free lessons on YouTube．People enjoyed watching the lessons on YouTube，and afterwards，many decided to go to David's own website．Now David sells hundreds of guitar lesson videos each week．
People also use YouTube to help others．Ryan Fitzgerald is one example．Ryan is friendly young man who knows that some people are lonely and have no one to talk to．One day，he made a video of himself for YouTube．In the video，he gave his phone number and invited people to call him．In a week，he had more than 5，000calls and messages from all over the world．These days，he is very busy talking on the phone．He helps people，but mostly，he just listens，like a friend．
Finally，some filmmakers use YouTube in a more serious way．They want to tell people about important events happening in the world．For example，they show clips（片段） of videos from countries at war，or they show people in need of help after a storm．Sometimes TV news shows do not give enough information about these events．Thanks to YouTube filmmakers，people can go to their computers and learn more．
For many people，YouTube is more than just another website to visit．It is a way to communicate with others．More and more people are using it every day，and they will probably find even more ways to use it．
51．From the first paragraph of the passage，we know three young menA．
A．set up a new website YouTube
B．sent a video by using the e-mail
C．shared a video right at a dinner party
D．became very popular in a few months
52．Which of the following is NOT true about YouTube？B
A．YouTube makes sharing videos easy．
B．Over 70，000filmmakers are not professionals．
C．Many videos on YouTube are short．
D．Most of the filmmakers are just everyday people．
53．Judson Laipply became popularB．
A．only because he was a good dancer
B．after he put his funny dance video on YouTube
C．because he wanted to make more dance videos for the website
D．because people watched all kinds of videos 10million times a week
54．YouTube is used by David TaubD．
A．to sell his guitars
B．to start his new business
C．to set up his own website
D．to advertise his business
55．Which of the following is NOT true according to the passage？C
A．People use the website YouTube to entertain others，or help others．
B．YouTube gives people a place to put videos so they can share or enjoy different shows．
C．Most of new videos made by professionals go up on YouTube every day．
D．For many people，YouTube is not only just a website to visit but also a way to communicate with others．
