题目

你了解自己吗？下列关于一个中学生的相关物理量估测值最合理的是（   ） A . 中学生的质量约为50g B . 中学生正常步行的速度约为1.1km/h C . 中学生站立时对地面的压强约为15kPa D . 中学生的体积约为50m3 答案：C If your pen broke at school today,what would you do?You would go to a shop and buy a new one.What if you could simply print out a real,working pen with your 3-D printer without leaving your room?Ten years ago people could only see 3-D printing in science fiction movies.But now 3-D printing is here and it’s bringing big changes.Unlike normal printing that can only copy a 2-D picture with ink.3-D printing can build almost anything made from material.The printer layers(分层) the material in different shapes to create the object you want to be copied.The 3-D printer has been used to make many different things.People have made cups cars and even an airplane with it.Doctors have been using 3-D printers for several years.People’s nervous systems have been printed out in 3-D form medical research.Some body parts have been printed and used in hospital.Several months ago,doctors used a 3-D printer to rebuild the face of a person who had a bad accident.In the future,it is expected that the printer will make human organs to save more lives.However there are drawbacks to the printer.At the moment,printing can be quite slow and it’s still rather expensive.The average(平均的) price of a household printer is around $1,700,not including the cost of the materials.But as the technology develops,it shouldn’t be long before disadvantages are improved.Only time will tell where this new technology will take us.根据短文内容，从题中所给的A、B、C、D四个选项中，选择最佳答案。1.People could see 3-D printing in_________ten years ago.A.large high school B.science fiction moviesC.digital camera shop D.hospital2.People still can’t make a(n)________with a 3-D printer so far.A.airplane B.face C.organ D.cars3.What does the underlined word “drawbacks” mean?A.不足 B.趋势 C.优点 D.影响4.Which of the following is TRUE?A.The normal printer can build 3-D objects you want.B.No nervous systems are printed out in 3-D form.C.The 3-D printing can be cheaper and faster in the futureD.There will be no drawbacks to the 3-D printing in the future.5.What’s the best title of the passage?A.The advantages of 3-D printingB.The disadvantages of 3-D printingC.The changes brought by 3-D printingD.The rapid development of science