D
Disease spread in many ways. An infected person can cough or sneeze on someone nearby, or they can spread germs through a handshake. But sometimes we pick up germs indirectly. A sick person might leave behind bacteria or viruses when they touch a door handle, for example. But what if those surfaces could clean themselves?
Two teenagers from Hong Kong asked themselves the same question. Now they’ve developed a door handle that can kill germs on contact.
The idea is simple: Every time the door is opened, the movement creates power that starts a germ-killing reaction on the handle. In lab tests, their system killed about 99.8 percent of the germs that they spread onto lab dishes covered with their material.
Research by others has shown that door handles in public areas are often home to lots of bacteria and viruses, notes 17-year-old Sum Ming(“Simon”) Wong. He and schoolmate Kin Pong (“Michael”) Li,18, wanted to design a covering for door handles that would kill germs.
After doing some research, they learned that a mineral called titanium dioxide is known to kill bacteria. It’s already used in many products, from paints to desserts. To make their covering, the teenagers made the mineral into a very fine powder.
Titanium dioxide kills bacteria best when lit by ultraviolet light, says Simon. UV light is found in sunlight. But UV light does not naturally shine on indoor handles or any used at night, so the teenagers light their door handle from within.
To make sure the light reaches the coated surface, the teenagers made their door handle out of clear glass, Each end fits into a bracket (托架). Inside one of the brackets is a strong light-emitting diode(LED).From it comes UV light.
And here’s the interesting part: The power that makes the UVlight shine comes from opening and closing the door. The power from the door is then carried by wire to the LED inside the door handle.
The door handle system, Michael and Simon say, might cost no more than about $13 (about 81 yuan) to build.
12. The ways diseases spread are mentioned at the beginning of the text to ________.
13. Michael and Simon’s door handle __________.
14. The LED is placed inside the brackets to _______.
15. What is the author’s attitude toward Michael and Simon’s door handle system?
本题考查一项可以通过摩擦运动可以杀死细菌的新发明的话题，推断判断题。根据第一段尤其是最后一句：“ But what if those surfaces could clean themselves?”可知这句是启下的意思，本段提到疾病传播的方式正是为了引出能够防止疾病传播的新发明，可知选项D.是正确的，所以选择D选项。
推断判断题。根据第一段尤其是最后一句：“ But what if those surfaces could clean themselves?”可知这句是启下的意思，本段提到疾病传播的方式正是为了引出能够防止疾病传播的新发明，可知选项D.是正确的，所以选择D选项。
推断判断错误。
本题考查一项可以通过摩擦运动可以杀死细菌的新发明的话题，事实细节题。根据第三段：“ Every time the door is opened, the movement creates power that starts a germ-killing reaction on the handle. ”每次门被打开的时候，门把手的摩擦运动会制造电源来开始杀菌，可知选项B.is powered by the movement of its users。门把手的电源来自于门的使用者的摩擦动作是正确的，所以选择B选项。
事实细节题。根据第三段：“ Every time the door is opened, the movement creates power that starts a germ-killing reaction on the handle. ”每次门被打开的时候，门把手的摩擦运动会制造电源来开始杀菌，可知选项B.is powered by the movement of its users。门把手的电源来自于门的使用者的摩擦动作是正确的，所以选择B选项。
事实细节把握不到位。
本题考查一项可以通过摩擦运动可以杀死细菌的新发明的话题，推断判断题。根据第六段：“Titanium dioxide kills bacteria best when lit by ultraviolet light, says Simon. ”二氧化钛被紫外线光点亮时就能够杀菌。和第七段：“Inside one of the brackets is a strong light-emitting diode(LED).From it comes UV light.”在支架里安装着一个很强的发光二极管，它就可以发射出紫外线，可知选项C.provide UV light to help titanium dioxide work better为了提供紫外线帮助二氧化钛更好地杀菌是正确的，所以选择C选项。
推断判断题。根据第六段：“Titanium dioxide kills bacteria best when lit by ultraviolet light, says Simon. ”二氧化钛被紫外线光点亮时就能够杀菌。和第七段：“Inside one of the brackets is a strong light-emitting diode(LED).From it comes UV light.”在支架里安装着一个很强的发光二极管，它就可以发射出紫外线，可知选项C.provide UV light to help titanium dioxide work better为了提供紫外线帮助二氧化钛更好地杀菌是正确的，所以选择C选项。
推断判断错误。
本题考查一项可以通过摩擦运动可以杀死细菌的新发明的话题，推断判断题。根据全文，作者一直都在赞扬这项发明，所以对两位同学的门把手杀菌系统持有的是很热心、很感兴趣的态度，所以选择C选项。
推断判断题。根据全文，作者一直都在赞扬这项发明，所以对两位同学的门把手杀菌系统持有的是很热心、很感兴趣的态度，所以选择C选项。
推断判断错误。