Unit 6 Space and beyond 一、阅读理解 A [素材创新/]During space missions， astronauts can experience a loss of some of the inner structural support in their bones， reducing the density（密度） of them. For trips in space lasting at least 6 months， the bone loss is equal to about 20 years of aging. Fortunately， a new study finds a year back on earth rebuilds about half of strength lost in the affected bones. "Our bones are always remodeling（重塑），" notes exercise scientist Leigh Gabel. "But they’ll lose some of their strength when in space." Gabel was part of a team that tracked 17 astronauts. Each of these 14 men and 3 women had spent from 4 to 7 months in space. The team measured the 3-D structure of their bones. They focused on the structure of the tibia（胫骨） in the lower leg and the lower-arm bone. The researchers took images of the bones 4 times — before spaceflight， then when the astronauts returned from space， and again six months and one year later. From the pictures， they got to know an astronaut’s bone strength and density at each of those times. Astronauts in space for less than six months recovered their preflight bone strength after a year back on earth. But those who stayed in space longer suffered permanent bone loss in their tibias. That loss was equal to a decade of aging. The lower-arm bones showed almost no loss. That was likely because these aren’t weight-bearing bones on earth， Gabel explains. In fact， those arms can get a bigger workout in space than on earth as astronauts use them to move around their craft by pushing off handles and doorways. "Increasing weight-lifting exercises in space could help reduce bone loss in legs，" says exercise scientist Steven Boyd. "With longer spaceflight， we can expect bigger bone loss — and probably a bigger problem with recovery，" says physiologist Laurence Vico. "Space agencies should also consider other bone heath measures to reduce bone loss and increase bone formation." 身处太空中的宇航员会出现骨质流失的情况，而且他们在太空中待的时间越长，这种情况会越严重。如果待的时间少于6个月，返回地球一年后，骨骼强度会恢复到进入太空前的状态；时间超过6个月的话，骨质流失将会是永久性的。 1. What may the author think of the new study’s discovery？ A. It shows bone loss in space can be ignored. B. It’s really beyond the researchers’ expectations. C. It shows people on earth don’t suffer bone loss. D. It’s probably good news for astronauts back from space. 解析 D 细节理解题。由第一段中的"Fortunately， a new study finds a year back on earth rebuilds about half of strength lost in the affected bones"可知，研究的发现对于从太空归来的宇航员来说理应是好消息，故本题选D。 2. What does Para. 3 mainly talk about？ A. The focus of the researchers’ study. B. How Gabel’s team carried out their research. C. Why the researchers took pictures 4 times. D. Changes of the astronauts’ bone strength and density. 解析 B 段落大意题。通读第三段可知，本段主要讲述的是Gabe ... ...
