passage 2

　　the intrepid voyager 1 and 2 spacecrafts were launched in 1977， and despite having a roughly 12—year mission lifespan， are still hurtling through space and returning data to eager scientists on earth. they’ve broken through barrier that protects our solar system and are now zipping through the interstellar medium along with pioneer 10 and 11.

　　but how long might it take them， or another spacecraft， to actually reach another star system?

　　a team of scientists—coryn bailer—jones of the max planck institute for astronomy in switzerland and davide farnocchia of nasa’s jet propulsion laboratory—have done the calculations. essentially， the pair found a way to chart how long it would take a spacecraft to get from our humble solar system to the next system over， according to a paper scientists uploaded to the pre—print server arxiv.

　　in the quest for answers， farnocchia and bailer—jones turned to the european space agency's gaia space telescope for help. for more than five years， gaia has been gathering data on billions of stars， charting their orbits and path through the cosmos.

　　using this data and data about the projected paths of both the voyager spacecrafts as well as pioneer 10 and 11， which are careening toward the outer reaches of the solar system， the researchers were able to create a timeline of when these crafts might reach distant star systems. for those eager to visit other worlds， brace for some bad news.

　　should they continue their transit， the four spacecrafts will come within striking distance of approximately 60 stars in the next million years. and in that same amount of time， they’ll get even closer— try two parsecs， the equivalent of 6.5 light years—to about 10 stars.

　　who will have the best shot at reaching and exploring a distant star? pioneer 10 will swing within. 231 parsecs the star system hip 117795 in the cassiopeia constellation in approximately 90，000 years. and how long before one of these spacecrafts is hijacked by the orbit of one of these stars? it’ll be about 1，000，000，000，000，000，000，000 years.you’ll have some time to kill.

　　66.how long will it take spacecraft to distant stars? ()

　　a. 90，000 years.

　　b. 6.5 light years.

　　c. one billion years.

　　d. 1，000，000，000，000，000，000，000 years.

　　【答案】a。根据关键词定位至第二段，可知第二段提出了疑问but how long might it take them， or another spacecraft， to actually reach another star system?接着第三、四、五段进行了对这一话题的过程阐述，直到最后一段提到pioneer 10 will swing within…in approximately 90000 years可知飞船去最近星系需要90000年。选项中的6.5光年出现在插入语中，try two parsecs， the equivalent of 6.5 light years可知是对两(秒差距)天体间距离的解释;billion years在文中并未出现;选项d描述的是这些飞船被星系轨道控制之前的时间。故本题正确答案选a。

　　67.scientists calculated the timeline of when crafts will reach distant starsystems based on the data about ().

　　a. the projected paths of voyager spacecrafts as well as pioneer 10 and 11.

　　b. orbits and path of billions of stars through the cosmos.

　　c. path of billions of stars， voyager spacecrafts， and new pioneers.

　　d. speed of spacecrafts careening toward the outer reaches of the solar system.

　　【答案】c。根据第四段in the quest for answers， …turned to the… space telescope for help…gathering the data on billions of stars， charting their orbits and path through the cosmos.以及根据第五段using this data and data about the projected paths of both the voyager spacecrafts as well as pioneer 10 and 11…the researchers were able to create a timeline of when…可知科学家计算星系距离的时间线需要借助太空望远镜收集数十亿星星穿越宇宙的轨道和路径信息，同时根据“航行者号”和“先锋者10”“先锋者11”飞船的投影路径数据，科学家们才能计算出时间线。结合选项发现c项表达更全面，包含了选项ab内容。选项d内容是对“飞船”的解释说明。故本题正确答案选c。

　　68.which can be the best title of this passage?()

　　a.scientists calculated paths of voyager spacecrafts to a outer system.

　　b. scientists calculated the timeline of when voyager 1 and 2 escape the earth.

　　c. scientists calculated how long it’ll take to reach distant stars.

　　d. four spacecrafts will come within striking distance of approximately 60 stars to a outer system.

　　【答案】c。文章首段描述背景信息，第二段提出问题but how long might it take them， or another spacecraft， to actually reach another star system?后面段落围绕该话题展开。选项abd均为文中细节内容，只有c项是对主旨段落的同义替换。故本题正确答案选c。

　　69.()is needed to calculate orbits of billions of stars through the cosmos.

　　a. gaia space telescope

　　b. a super-computer

　　c. not mentioned

　　d. the pre-print server arxiv

　　【答案】a。根据文中第四段turned to the european space agency’s gaia space telescope for help…可知a项正确。选项d在第三段末出现，根据according to a paper scientists uploaded to the pre—print server arxiv.可知这是论文上传的地址。选项b：超级计算机，明显不符合文中表达。故本题正确答案选a。

　　70.which of the following about“voyager 1 and 2” is incorrect?()

　　a. scientists are yearning for the data they send back.

　　b. their life was 12 years when they were developed.

　　c. they are now moving through interstellar media to another star system.

　　d. they have exceeded their prescribed period in the space.

　　【答案】d。根据第一段the intrepid voyager 1 and 2 spacecrafts were launched in 1977， and despite having a roughly 12—year mission lifespan，(选项b同义替换) are still hurtling through space and returning data to eager scientists on earth(选项a同义替换). they’ve broken through barrier...and are now zipping through the interstellar medium(选项c同义替换)，可知选项abc都有提到，只有d项未提及。故本题正确答案选d。