Mn giúp mk 1 câu này đc kh    

Today, Internet has become an important part of our lives. We can use the internet to do shopping, pay bills, play games, make new friends and learn new things. More than four billion people around the world use the internet. Nevertheless, not everything about the Internet is good. First, many people spend too much time using the Internet. Some people become addicted to it when they use it 28 hours each week. Many people say that they cannot live without it. Second, some people always use the internet for their private purpose, which can make their boss angry and fire them. Third, when people use the internet so much, they may not be healthy because they have a sedentary lifestyle without doing exercise. Fourth, many people have “friends” on social networking sites such as Facebook, but they may not be real friends. Real friends are people you can see face- to- face. Two or three real friends are better than hundreds of Facebook “friends” that you never see. Finally, some people are criminals. They are bad people and they use the Internet to try to steal your money.

Question 43. The word “it” refers to_______

A.week                              B. time                             C. work                       D. the internet