20. The primary purpose of the passage is to% L" r1 }- t- w) A' A& Z; C
(A) describe the way in which hot spots influence the extinction of volcanoes: X& Q# {3 N* d. z& s3 U+ ^8 U. o! K
(B) describe and explain the formation of the oceans and continents
8 n* _' R3 L L# @4 N7 e (C) explain how to estimate the age of lava flows from extinct volcanoes
. e; {: D1 z- e3 g1 p ~ (D) describe hot spots and explain how they appear to influence and record the motion of plates' z2 J2 {3 x5 p, N2 A
(E) describe the formation and orientation of island chains in the Pacific Ocean" t# D0 D4 M k+ P
21. According to the passage, hot spots differ from most volcanoes in that hot spots* g" n0 c# @; j' r) R# x
(A) can only be found near islands. o" D" f0 p+ g) U
(B) are active whereas all other volcanoes are extinct/ e, _1 r5 d7 C! T* Z* ]
(C) are situated closer to the earth's surface
4 ]2 ^, ]' c" D7 S (D) can be found along the edges of the plates
( `5 f* E; p9 l: T5 I (E) have greater amounts of alkali metals in their lavas
8 E- f" O" ?) K: A# {6 [6 s% f1 E 22. It can be inferred from the passage that evidence for the apparent course of the Pacific plate has been provided by the
+ z8 R/ r! _! p) `4 h0 X! N6 i7 Y (A) contours of the continents.6 n& f3 x- \! Y0 {" o7 M/ s. v
(B) dimensions of ocean hot spots2 W- u7 n: }( I; h7 j6 ?/ o$ c
(C) concurrent movement of two hot spots
6 `* s, v, t9 X' {2 Z (D) pattern of fissures in the ocean floor) j5 r; h1 N8 a( J4 J
(E) configurations of several mid-ocean island chains
9 ?1 J, H& `6 q 23. It can be inferred from the passage that the spreading out of lavas of different ages at hot spots indicates that a* s( t+ |4 g* m( Q5 `2 t
(A) hot spot is active
- S- D6 A- u! E5 l( }, s0 K (B) continental plate has moved. z; ?9 X9 W( M% x/ I' X
(C) continental rupture is imminent
- q; J9 \* F: Z; e (D) hot spot had been moving very rapidly
! @1 K2 P* g9 \7 w! a, |& K& } (E) volcano contains large concentrations of alkali metals
/ j5 v$ \0 ~" T& J) n5 i 24. The passage suggests which of the following about the Hawaiian Islands, the Austral Ridge, and the Tuamotu Ridge?0 a( k* T: r- U' a; [
(A) The three chains of islands are moving east- ward.
% F& r& W/ W0 D# n6 @ (B) All the islands in the three chains have stopped moving.- b2 b- C6 b. z" Y, N; E
(C) The three islands chains are a result of the same plate movement.
2 E1 B9 ?. U9 |0 n* J/ U3 S! d (D) The Hawaiian Islands are receding from the other two island chains at a relatively rapid rate.- e( N8 T( I4 j4 a
(E) The Austral Ridge and the Tuamotu Ridge chains have moved closer together whereas the Hawaiian Islands have remained stationary.6 Q0 h }) `4 Q; F6 v! `
25. Which of the following, if true, would best support the author's statement that hot-spot activity may explain the mutability of continental plates?
e. J; o- w7 D; D7 B K2 b (A) Hot spots move more rapidly than the continental and oceanic plates.
* F/ I. ?* b- t: j (B) Hot spots are reliable indicators of the age of continental plates.
% `6 W0 T+ U. ]( o, k (C) Hot spots are regions of volcanic activity found only in the interiors of the continental plates.
! Z% k# a8 O u1 E$ U2 v (D) The alignment of hot spots in the Pacific. Ocean parallels the alignment of Pacific Ocean islands.
/ G/ Q: l" I) L2 Q+ g' b9 V5 S (E) The coastlines of Africa and South America suggest that they may once have constituted a single continent that ruptured along a line of hot spots.( {8 x/ s' w0 L" M, L1 R% U
26. The author's argument that hot spots can be used to reconstruct the movement of continental plates is weakened by the fact that" Z* F) {' Q9 z" R$ \* O$ v
(A) hot spots are never found at the boundaries of plates% M) Z* W5 e5 p
(B) only extinct volcanoes remain after a plate moves over a hot spot _5 K8 p K+ m0 }
(C) lava flow patterns for all hot spots have not been shown to be the same
/ X* A0 u" W2 z6 C! R# F% c s0 | (D) the immobility or near immobility of hot spots has not been conclusively proven- i* B. q2 b6 \0 M
(E) the changing configurations of islands make pinpointing the locations of hot spots difficult( ^: u. R& p+ Z' f+ ^
27. The author's style can best be described as
- V; m' q0 N* s3 o* ? (A) dramatic来www.Examw.com
2 ~- G, [& b G8 I: U2 u/ y (B) archaic
. a+ I- u; p! I; R5 H: j+ D (C)esoteric
3 I/ z2 g, z& A, A& m (D) objective4 ^; E$ D7 `# p, b' W+ b
(E) humanistic
) ~# r/ {+ I; ^( s; s" w0 } 28. SUBTLE:/ O2 ?9 T0 W# b& F' x2 ~
(A) careful4 ~1 m. b" u' k
(B) dirty6 o- }; O& E- E- U; X) i
(C) obvious
2 P. ^1 R# g7 q (D) intentional$ [. D6 J3 t: B+ D3 q
(E) eager |
发表于 2012-8-15 12:45:20
