12．From VOA Learning English，this is the Technology Report．
Researchers are now using three-dimensional，or 3D printing to create models of the human heart to help heart specialists．The heart doctors can use the models to better help patients before an operation．
Surgeons regularly use digital images to explore the heart in close detail．But no two human hearts are alike．This led Matthew Bramlet to create exact heart models from those images．Dr．Bramlet is a pediatric or children's heart expert at the University of Illinois College of Medicine．He says the 3-D models show information he cannot get any other way．
A 3-D printer uses images from a digital display to create a physical model of a human heart．Matthew Bramlet says doctors can use the model，in his words，"to understand the anatomy for the first time．""Even when I will take the MRI and render the images，even a print heart that is sort of spinning on the screen，it's still a 2-D screen．Now we've pulled it out of the screen so that you can actually hold it in your hand arid evaluate the anatomy for the first time in a manner that makes sense and is logical．"
Pictures from medical tests like CAT scan or MRI are sent to a 3-D printer to create a heart in a plaster or clay form．The printer then constructs the heart，thin layer by thin layer．Dr．Bramlet says the model matches the real heart in every detail．"When we're done with the model and make our decision，we want to be able to go back to the source image and confirm those findings，"he says．
Dr．Bramlet has built model hearts for different kinds of heart operations．All of the operations were successful．In his first ease，digital images showed only one tiny hole in a baby's heart．But，the 3-D printed model showed several defects or problems that the baby was born with．Dr．Bramlet says those defects could not be seen easily in the images．The heart surgeon was able to change the type of surgery for the patient based on the 3-D model．He added that 3-D heart models save time during heart operations．
Kathy Magliato is a cardiac surgeon at Saint John's Health Center in Los Angeles．She welcomes the new technology．She says it could help her make better decisions before she operates on the hearts of her patients．"The fact is that I can then take this very complicated structure，which has endless possibilities of what it could look like anatomically when I open body，and you give it to me before the operation and I can hold it in my hand and plan an operation around what I'm seeing，touching and feeling．That to me is what can potentially change the game in an operation and save lives．
Matthew Bramlet continues to research the technology．He is working with the National institutes of Health to build a 3-D library that includes heart models and images that others can use．
67．As a helper to surgeons，what's the major advantage of 3D-printing？D
A．It can be applied to different kinds of operations．
B．It can provide digital images in detail．
C．It can shorten time during heart operations．
D．It can create a heart model with detailed information．
68．What do we know about the 3-D printed heart model？C
A．It is shaped in one step．
B．it can only be made of clay．
C．It is based on medical tests．
D．It can only be observed on the screen．
69．What does the underlined sentence in the last but one paragraph imply？D
A．Any change may happen in an operation．
B．Any change in an operation can't be ignored．
C．A 3-D printed heart model is a change to a regular operation．
D．A 3-D printed heart model may contribute to adjustment to an operation．
70．What could be the best title for the Technology Report？C
A．Advantages of 3D-printing
B．Features of 3D-printing
C．A new dimension to heart surgery
D．A fundamental reform to heart surgery．
分析 本文主要讲述了研究人员目前正在使用三维，或者3D打印技术创造的人类心脏模型帮助心脏专家，手术之前心脏医生可以使用模型来更好的帮助病人．
解答 67．D 细节理解题．根据文章第三段可知3D-printing的主要优点是"能制造出含有详细信息的心脏模型"． C不是主要优点．
68．C 细节理解题．根据第五段第一句可知medical tests是"基础"；有plaster or clay两种形式，可知B错误．根据第五段第二句可知模型是一层层制成，因此A一步成型是错误的．
69．D 词义猜测题．That指的是a heart model，potentially意为"潜在地，可能地"，因此该句的意思是"心脏模型对于我就是可能改变手术进程从而挽救生命的东西"．
70．C 主旨题．文章主要讲述运用3D打印技术对心脏手术带来的变化．A、B标题过大，本文只是这项技术在心脏手术这一个方面的应用．D．fundamental不正确．C不仅能总结文章的主旨大意，而且一语双关：a new dimension既是指3D相对于2D，增加了一维，又指为心脏手术开拓了新的层面．
点评 做这类题材阅读理解时要求考生对文章通读一遍，做题时结合原文和题目有针对性的找出相关语句进行仔细分析，结合选项选出正确答案．推理判断题也是要在抓住关键句子的基础上合理的分析才能得出正确答案，切忌胡乱猜测，一定要做到有理有据．
