第6部分：完形填空 (第5l～65题，每题1分，共1 5分)+ h' p2 Q# j e" u) H+ E
阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案，涂在答题卡相应的位置上。
- i& M- u* h! E+ R# t1 W Earth’s Inner Core% q$ j8 o4 ~$ Z: v
Scientists have long struggled to understand what lies at the planet’s center, Direct" `5 g# m; ?1 w2 y9 ~
observation of its center is impossible，so researchers must_____(51)to other evidence．- Y/ T/ Q, C2 e: I8 W
In 1889，a German scientist detected a severe earthquake in Japan．Geophysicists concluded
, Y; L, F: M$ R4 o2 x! B7 c$ L that shock waves_____(52)jolts(晃动)from one side of Earth through the center to the
# U6 d$ {- `3 @+ p/ Y1 o. B* E other side．Then in 1936，Danish geophysicist Inge Lehmann studied the waves______(53)) q- W# L, W# U* a- r
to determine that within Earth’s core of molten(熔化了的)iron lies a solid inner core-but_____
6 ]- ]! g3 j: r1 y [% ^ (54)that core was made of eluded(难倒)her．Other geophysicists quickly
0 x. G& _5 {0 x7 S determined that Lehmann’s inner core was composed mostly_____(55)iron. Since then，/ s8 ?1 v& j2 F5 `; T9 k" \) Z
Lehmann’s discovery has_____(56)conventional Earth science．
0 Y9 s8 {0 G6 K- l: G& b But now scientists are challenging traditional theory with new and radical _____(57)
* u" [$ I# |7 Y) t: Z- r8 ^' K For example，Earth’s center could actually contain an“inner core within the inner core，claim Ishii and colleague Adam Dziewonski．; a" X" s. _1 ?4 R) p
Analyzing hundreds of thousands of earthquake wave _____(58),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____(59)from the formation of Earth，”says Dziewonski．
0 K* Q) _3 @5 s0 n Q Dziewonski and Ishii speculate that shortly_____(60) Earth formed around 4.8billion years ago，a giant asteroid(小行星)smashed into the young planet and nearly melted it. But Earth’s center didn’t quite melt；it______(61)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_____ (62)of the planet，”Dziewonski says idea is tame(温和的)compared to the_____(63)theories of independent geophysicist J．Marvin Herndon．Earth’s inner core is made not of iron，he claims Y+ X" z/ r: ^) v' m/ G
but a_____(64)of nickel and silicon Hemdon 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．Hemdon thinks the uranium releases heat energy as its atoms_____(65)fission-split and crash into another in a chain reaction. In other words,we may live on top of a gigantic, “natural”nuclear power plant.
7 \# j' X6 J$ y) t2 c/ Y5 V 51 A try B leave C turn D point! C% q: H, V4 y. c L. `$ S7 ]5 N
52 A create B receive C feel D overcome1 L u$ B" D% C, m0 T1 B' t
53 A work B solution C job D patterns
$ J; s) B( {6 z 54 A whether B what C why D how
x& A& J u5 r! [1 V; q 55 A from B within C of D to. ~& _4 t% ]1 k* S
56 A followed B dominated C restored D opposed
4 b& u$ w$ P! m; a 57 A ideas B demands C phenomena D movements
& P% f" E6 \0 n7 d$ x9 x1 @ 58 A things B acts C methods D records' A$ ]) u3 z; J7 K! g- N. Y9 t! u
59 A taken B benefited C left D kept. Z+ Q2 C/ N$ Z6 N: _
60 A after B before C since D when" ?4 Q2 V# C' E# H9 u
61 A expanded B modified C gained D melted. J1 Y0 S: ]1 ?( A* [
62 A size B origin C structure D shape
- m3 D( r4 _) ?: _+ g6 u$ f$ W 63 A radical B traditional C classical D conventional
6 p3 B/ n: f3 u% c; z7 K9 O$ D. | 64 A system B copy C model D compound5 D$ B2 ]2 n9 B) y6 M
65 A charge B last C experience D show |
发表于 2012-8-15 23:23:33
