What is the coldest air temperature ever recorded on the Earth? Where was this low temperature recorded? The coldest recorded temperature on Earth was -91℃, which (51) in Antarctica in 1988. We encounter an interesting situation when we discuss temperatures in (52) . Temperatures in Earth orbit actually range from about 20℃ to 120℃. The temperature depends upon (53) you are in direct sunlight or shade. Obviously, -120℃ is colder than our body can safely endure. Thank NASA science for well-designed space (54) that protect astronauts from these temperature extremes. The space temperatures just discussed affect only our area of the solar (55) . Obviously, it is hotter closer to the Sun and colder as we travel away from the Sun. Astronomers estimate temperatures at Pluto are about -210℃. How cold is the lowest estimated temperature in the entire universe? Again, it depends upon your (56) . We are taught it is supposedly (57) to have a temperature below absolute zero, which is -273℃, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully cooled down a gas to a temperature barely (58) absolute zero. They won a Nobel Prize in Physics in 2001 for their work—not a discovery, in this case. Why is the two scientists work so important to science? In the 1920s, Satyendra Nath Bose was studying an interesting (59) about special light particles we now call photons. Bose had trouble (60) other scientists to believe his theory, (61) he contacted Albert Einstein. Einstein's calculations helped him theorize that atoms (62) behave as Bose thought—but only at very cold temperatures. Scientists have also discovered that (63) atoms can help them make the world's atomic docks even more accurate. These clocks are so accurate today they would only lose one second (64) six million years! Such accuracy will help us travel in space because distance is velocity times time (d=vt). With the long distances involved in space (65) , we need to know time as accurately as possible to get accurate distance.
【答案解析】[解析] 上文说-120℃是宇航员无法忍受的温度，下文说美国国家航空和航天管理局生产出某种装置以“protect astronauts from these temperature extremes”(保护宇航员不受极端温度的侵害)。很明显，这一装置就是“space suits”。故本题选D。
单选题
A. ultra-small B. ultra-fast C. ultra-hot D. ultra-cold
【正确答案】
D
【答案解析】[解析] Wornell and Wieman荣获诺贝尔物理奖，是因为他们成功地将气体的温度降到接近零度。本文最后两段以实际例子说明他们的成就推动了科学的发展。因此，ultra-small，ultra-fast和ultra-hot都与Cornel and Wieman的研究无关联，不会是答案。只有ultra-cold才是合乎逻辑的选项。故本题选D。
单选题
A. any B. each C. every D. Some
【正确答案】
C
【答案解析】[解析] 从句子“These clocks are so accurate today they would only lose one second six million years!”推断，原子钟如此精确，每隔600万年才慢1秒。“每隔”的英语用词是every。故本题选C。