A
(2019·广东模考)We have all been there. In a rush to leave the house we grab our phones ahead out of the door, realizing all too late that the battery is dead because we forgot to plug it into the table cloth. Or perhaps we have not. But this could be in future that scientists hope to explore with electronic sheets that charge our mobile phones, laptops and other equipment by harvesting energy from the world around us.
In a step in that direction, scientists at Massachusetts Institute of Technology (MIT) have created superthin, bendy materials that absorb wireless Internet and other electromagnetic waves in the air and turn them into electricity. The lead researcher, Tomas Palacios, said the breakthrough smoothed the way for energyharvesting covers ranging from table cloths to giant packing for buildings that catch energy from the environment to power sensors and other electronics.
Palacios and his colleagues connected a bendy antenna (天线) to a flexible semiconductor (半导体) layer only three atoms thick. The antenna picks up wifi and other radio frequency signals and turns them into a current. This flows into a special semiconductor, where it is changed into a direct electrical current. Researchers have made energyharvesting “rectennas (整流天线)” before, but existing equipment is made from conventional semiconductors which are inflexible, fragile and practically impossible to make in large sheets.
The wifi signals can fill an office with more than 100 microwatts of power that is ripe to be collected by energyharvesting equipment. The MIT system has an efficiency (效率) of between 30% and 40%，producing about 40 microwatts when exposed to signals bearing 150 microwatts of power in laboratory tests. “It doesn't sound like much compared with the 60 watts that a computer needs, but you can still do a lot with it，” Palacios said. “You can design a wide range of sensors, for environmental monitoring or chemical and biological sensing, which operate at the single microwatt level.”
Medical equipment is another potential application. Because wifi and similar radiofrequency signals pass through people, energyharvesting covers could be applied to implanted sensors to provide them with enough power to send out health data to an outside receiver.
1．What does the underlined word “it” in Paragraph 1 refer to?
A．The phone. B．The door.
C．The sheet. D．The table.
答案：A 指代判断题。上文提到你匆忙拿着手机出门，结果发现手机没电了，因为你忘记把它插入桌布了。故it代指手机。
2．What is special about the new breakthrough?
A．It can harvest wifi energy.
B．It is super thin and flexible.
C It can power all the electronics.
D．It smoothes the way of receiving signals.
答案：B 细节理解题。由第二段中的“superthin, bendy materials”可知，重大突破就是超薄、灵活。
3．What is the main idea of the last paragraph?
A．Another energy harvesting equipment.
B．The function of the health data receiver.
C．Another potential application of the new equipment.
D．The way to implant the new equipment into the patient.
答案：C 段落大意题。由主题句“Medical equipment is another potential application.”可知，本段主要讲了新设备的另一个潜在应用。
grab v. 抓住；攫取 battery n. 电池 conventional adj. 符合习俗的，传统的；常见的；惯例的
第二段第二句：The lead researcher, Tomas Palacios, said the breakthrough smoothed the way for energyharvesting covers ranging from table cloths to giant packing for buildings that catch energy from the environment to power sensors and other electronics.
译文：首席研究员Tomas Palacios说，这一突破为能源收集罩的发展铺平了道路，包括从桌布到建筑物的巨型包装。这种能源收集罩能从环境中获取能量，并为传感器和其他电子设备提供动力。
分析：这是一个主从复合句，said后面是一个省略了that的宾语从句。而宾语从句中又含有一个定语从句，由that引导，修饰先行词covers。
