第6部分:完形填空:考查应试者正确把握文章内容,以及在一定语境中准确使用词语的能力。本部分为1篇300~450词的短文,文中有15处空白,每处空白给出4个选项,要求应试者根据短文的内容从4个选项中选择l个最佳答案。
Earths Inner Core
Scientists have long struggled to understand what lies at the planets center. Direct observation of its center is impossible, so researchers must (1) to other evidence.
In 1889, a German scientist detected a severe earthquake in Japan. Geophysicists concluded that shock waves (2) jolts (晃动) from one side of Earth through the center to the other side. Then in 1936, Danish geophysicist Inge Lehmann studied the waves (3) to determine that within Earths core of molten (熔化了的) iron lies a solid inner core - but (4) that core was made of eluded (难倒) her. Other geophysicists quickly determined that Lehmanns inner core was composed mostly (5) iron. Since then, Lehmanns discovery has (6) conventional Earth science.
But now scientists are challenging traditional theory with new and radical (7). For example, Earths center could actually contain an inner core within the inner core, claim Ishii and colleague Adam Dziewonski.
Analyzing hundreds of thousands of earthquake wave (8), they maintain that the inner core has at its heart a tiny, even more solid sphere (球体). This sphere may be the oldest fossil (9) from the formation of Earth, says Dziewonski.
Dziewonski and Ishii speculate that shortly (10) Earth formed around 4.8 billion years ago, a giant asteroid (小行星) smashed into the young planet and nearly melted it. But Earths center didnt quite melt; it (11) mass as the planet cooled. The core within a core may be the kernel (核心) that endured. Its presence could change our basic ideas about the (12) of the planet, Dziewonski says.
Dziewonskis idea is tame (温和的) compared to the (13) theories of independent geophysicist J. Marvin Herndon. Earths inner core is made not of iron, he claims, but a (14) of nickel and silicon. Herndon has a truly revolutionary notion: Within the nickel silicide (硅化物) inner core is also an inner inner core - an 8 km-wide ball of the element uranium. Uranium is radioactive. Herndon thinks the uranium releases heat energy as its atoms (15) fission-split and crash into one another in a chain reaction. In other words, we may live on top of a gigantic, natural nuclear power plant.
1 A try B leave C turn D point
2 A create B receive C feel D overcome
3 A work B solution C job D patterns
4 A whether B what C why D how
5 A from B within C of D to
6 A followed B dominated C restored D opposed
7 A ideas B demands C phenomena D movements
8 A things B acts C methods D records
9 A taken B benefited C left D kept
10 A after B before C since D when
11 A expanded B modified C gained D melted
12 A size B origin C structure D shape
13 A radical B traditional C classical D conventional
14 A system B copy C model D compound
15 A charge B last C experience D show
参考答案:
1. C 2. A 3. D 4. B 5. C 6. B 7. A 8. D 9. C 10. A 11. C 12. B 13. A 14. D 15. C
特朗普退出武器协议,俄罗斯要求解释
新研究:生孩子会严重打击女性的自尊心
国际英语资讯:India inks missile deal with Russia
体坛英语资讯:Coric sends Croatia to its third Davis Cup final
体坛英语资讯:Griezmann helps Atletico take second win in Champions League Group A
国内英语资讯:China mulls 2nd draft revision on rural land contract law
体坛英语资讯:US Open champion Osaka confident on first day of China Open
体坛英语资讯:Barcelona look for winning start in Champions League
娱乐英语资讯:Feature: Egyptian university students enchanted by traditional Chinese music
体坛英语资讯:Barca retain 100 percent record in Spains matchday 4
国际英语资讯:India, Russia talks to focus on energy, space during Putins visit
国内英语资讯:17th National Congress of ACFTU opens
国内英语资讯:Chinese embassy lashes out at Australian senators accusation against China
体坛英语资讯:Freiburg, Nuremberg secure late draws in German Bundesliga
体坛英语资讯:Feature: New Bayern coach Kovac sets sights on Champions League
体坛英语资讯:Namibia crash out of womens regional soccer tournament
体坛英语资讯:Dortmund whitewash Monaco 3-0 in UEFA Champions League
国内英语资讯:Tasks set out for advancing law-based governance in China
国内英语资讯:Beijing develops self-driving sanitation vehicle
体坛英语资讯:Kipchoge to defend Olympic marathon title at Tokyo 2020 Games
体坛英语资讯:Red Star, Napoli tied at the start of UEFA Champions league group stage
体坛英语资讯:Kenyan marathoner Cherono to challenge Bekele in Amsterdam
国内英语资讯:China sees domestic tourism boom during National Day holiday
国际英语资讯:Juncker hopes to reach Brexit deal in November
国内英语资讯:Chinese envoy asks for efforts to tackle imbalanced development
“哈佛学霸学习攻略”火遍社交媒体,作者竟是“虎妈”的女儿!
国内英语资讯:Draft law revisions suggest public supervision on judicial work
国际英语资讯:Pompeo meets with Pakistani FM on ties
研究显示 每天只喝一杯酒也会出现健康问题
体坛英语资讯:CONMEBOL seeks change to Copa America cycle