Big data（数据） is a lot of sets of information that are put together so they can be used by a computer program． The computer program looks for different kinds of answers or patterns in the data． Big data can have different kinds of information from many sources， such as information that comes from schools，social media sites， companies， and governments． One set of data can have people's names and addresses． Another set can have what they like， where they go to school， and how much time they spend on the computer．

    Big data can be used in many ways． The government uses it to understand how many people travel on buses or trains． This information is then used to make bus or train systems better． Some schools use big data to understand which children may need extra help in class． The teacher can then give certain students more help or support so those students can succeed in school． Companies use big data， too．It helps them understand who buys their products． For example， one company uses weather data to see when people eat the most ice cream．

    Big data can be used for good reasons． Some hospitals use big data to predict if a baby who is born too early will get sick． The hospital can then take extra steps to take care of that baby so he or she does not get sick． Big data can also be used for bad reasons． It can be used to predict which kinds of people are likely to break the law or hurt others， even if they have not done anything wrong．

    How can big data be used for good and bad things？ It is because the computer programs used to look at big data and understand it are written by people． People think a certain way． Because they think a certain way， they build a model of those ideas． These ideas are then used to look at the data．Sometimes，these ideas are helpful for people or businesses． Other times， bad ideas can cause problems for certain groups of people．

（1）This reading is about 　　．

A．what big data is and how it is used

B．what schools and hospitals people like

C．where important data is collected and stored

D．how big data is controlled by governments and companies

（2）One company uses weather information to 　　．

A．help children in need

B．know when people will visit the hospital

C．find out who rides the bus or train

D．understand when people will need ice cream

（3）The main idea of Paragraph 3 is 　　．

A．big data can be used for good reasons

B．we can use big data in a number of ways

C．big data can be used for both good and bad reasons

D．we can use big data to prevent babies from getting sick

（4）The overall tone（总基调） of this reading is 　　．

A．sad and personal

B．personal and scientific

C．informative but silly

D．scientific and informative