Câu hỏi:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions. 

           People used to know more or less how their children would live. Now things are changing so quickly that they don’t even know what their own lives will be like in a few years’ time. What follows is not science fiction. It is how experts see the future.

          You are daydreaming behind the steering wheel; is it too dangerous? No! That’s no problem because you have it on automatic pilot, and with its hi-tech computers and cameras, your car “know” how to get you home safe and sound.

          What is for lunch? In the old days you used to stop off to buy a hamburger or a pizza. Now you use your diagnostic machine to find out which foods your body needs. If your body needs more vegetables and less fat, your food-preparation machine makes you a salad.

          After lunch, you go down the hall to your home office. Here you have everything you need to do your work. Thanks to your information screen and your latest generation computer, you needn’t go to the office any more. The information screen shows an urgentmessage from a co-worker in Brazil. You can instantly send back a reply to him and go on to deal with other matters.

According to the passage, what do people use a diagnostic machine for?