17. The author focuses primarily on " X" J: S9 ]0 Q' o- N
4 W; p$ [5 Z# T (A) presenting two competing scientific theories concerning solar ) e" p3 C2 u5 C5 s- R0 _; h
- V' |% Z& _% R, W8 W activity and evaluating geological evidence often cited to support them
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(B) giving a brief overview of some recent scientifrc developments : w3 G& O/ t) }0 e8 Q; L6 }
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in s'olar physics and assessing their impact on future climatological research 3 e3 {: [- @1 A- R
8 d9 @5 n8 T/ X7 Q% S/ D* Y+ _ (C) discussing the difficulties involved in linkinl: ter- restrial * n* c: w- {9 c/ A, F4 E
5 g# s1 x8 }, I0 Z# D$ R4 ~ phenomena with solar activity and indicating how resolving that issue
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0 h9 S& ^! o: V: P could have an impact on our understanding of solar physics 7 \4 ^+ Z8 p# D* u
* |! m# e$ E3 ]( t9 F (D) pointing out the futility of a certain line of sci- entific inquiry 6 p. u$ V( M& p2 S F
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into the terrestrial effects of solar activity and recommendine ita
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aban- donment in favor of purely physics-oriented research . K y; P8 u5 f; k8 f
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(E) outlinine the specific reasons why a problem in solar physics has 0 ~% p% q/ u: J. V9 x; V' x
# _9 q5 ~- }3 |& q! P not yet been solved and faulting the overly theoretical approach of modern " o( f+ P$ z* A, ^( Q
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physicists. 6 z$ _2 z( O7 x ~0 d* {
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18. Which of th.e following statements about the two models of solar " |0 a! w; F" D# `* Q
% }4 t' ?1 q, I' c& Y+ N8 E1 u activity. as they are described in lines 37-55, is accurate? - _2 _4 q; s$ j% l F6 H6 \! e
( Q0 s& D* S0 o7 D) \; L
(A) In both modgls cyclical solar activity is regarded as a long-lived 7 s. t! \) A) u5 D1 U7 s
; A+ H. P0 T E# d# @ feature of the Sun, persisting with little change over billions of years.
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(B) Tn both models the solar-activity cycle is hypothesized as being 9 j) _! W3 Y) {4 v4 h
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dependent on the large-scale solar magnetic field.
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(C) Tn one model the Sun's magnetic fieid is thought to play a role in
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( e; [4 g: {! x; Q1 p causing solar activ- ity, whereas in the other model it is not. : B7 ]* K5 p2 W; w& s8 B
. p' A9 V& T8 M7 K (D) In one model solar activity is presumed to be unrelated to terrestrial
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( q1 M9 t/ M5 n: C" I! V- L. s3 p phenomena. whereas in the other model solar activity is thought to have
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# }: g. {, c _! y3 x observable effects on the Earth. 3 K' ~! r) x8 A: ?* h* f6 a1 _) O( e
, T& h2 K% ~ V1 f (E) In one model cycles of solar activity with peri- odicities longer than ; D/ u- A9 a* ~# S5 \, l! H4 t
' l; L- ?! t3 x" V) G a few decades are con- sidered to be impossible, whereas in the other model
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such cycles are predicted. |
发表于 2012-8-15 12:40:43
