At the heart of a comer's coma lies a nucleus of solid material, typically no more than 10 kilometers across.
2 C& S3 f q$ p% C7 mThe word "heart" is closest in meaning to which of following?, p* a. Q3 [+ X2 e
(A) center
& P: ~ H; D/ L8 @; P(B) edge3 C, s3 n* }& i" R
(C) tail7 U: T# R4 r# C1 P5 \0 S' ^* w: u
(D) beginning
0 u7 d4 H' U: `' I) _: k; n3 J; g. |4 ^$ K2 Q( N3 v
The most graphic proof that the grand spectacle of a comet develops from a relatively small and inconspicuous chunk of ice and dust was the close-up image obtained in 1986 by the European Giotto probe of the nucleus of Halley's Comet.) h/ N; U( g4 N# C g: |
The word "graphic" is closest in meaning to which of following?( l# ]2 G8 Q0 l' o" O+ R* C# L
(A) mathematical5 ] ?: C/ N( l1 c
(B) popular5 Z3 }; g3 c' i' \. b' g
(C) unusual& y' a G9 b2 G( j
(D) vivid
& w1 ^; J$ f4 u. H- N9 K$ k- A) L5 p. z
403. As a comet's orbit brings it closer to the Sun, first the coma grows, then two distinct tails usually form.
& X- \" K- W/ X7 g" P' aThe word "distinct" is closest in meaning to which of following?
- h2 j, o7 \3 B0 E(A) visible- c0 o2 G- ]6 r
(B) gaseous
1 b- Q6 f+ ?/ K7 x5 ?(C) separate- F. U3 c. ?+ Q! V( Y
(D) new
3 [2 i; z& B) v: N
' S$ a- O% F# |" |+ Z. Pheromones are substances that serve as chemical signals between members of the same species.7 r1 f2 o; h4 I) o$ |
The word "serve" is closest in meaning to which of following?, K# d* g2 k) i; U
(A) improve: k$ K8 G4 C: V. S/ H- K( T0 \ F
(B) function9 B' M9 d, O: B& y) T
(C) begin
: k/ n2 D0 ?' q1 ^2 d(D) rely
) }% {# J0 ~2 g, h3 G2 S, I" l. k: {, ~5 O: s( `
. Pheromones are the predominant medium of communication among insects (but rarely the sole method) . Some species have simple pheromone systems and produce only a few pheromones, but others produce many with various functions.5 w7 w3 Z+ |% G4 H- c
The word "sole" is closest in meaning to which of following?7 M/ G* w) ?1 Z, s7 m( j
(A) obvious
0 z8 f( A' s; b, R/ x; p( t. k(B) best
9 e9 R& T2 r3 s w9 r8 m4 q( `(C) only
8 R _( o# z% h$ X( p(D) final: t- E4 G$ O+ m8 X
ADCBC |
发表于 2012-8-14 22:41:43
