The first birds appeared during late Jurassic times. These birds are known from
+ i/ T' M D( s+ u+ w9 W# tfour very good skeletons, two incomplete skeletons, and an isolated feather, all from
9 d1 t5 }* Q6 ?( W Y, c6 Sthe Solnhofen limestone of Bavaria, Germany. This fine-grained rock, which is 7 H# S! z+ g0 j' U0 T
extensively quarried for lithographic stone, was evidently deposited in a shallow ) C! m1 T; s* s3 Y$ \% x: g0 K
(5) coral lagoon of a tropical sea, and flying vertebrates occasionally fell into the water
0 B: p) `; ~% f6 q! _and were buried by the fine limy mud, to be preserved with remarkable detail In this
& ]8 W+ w# v. G, Kway, the late Jurassic bird skeletons, which have been named Archaeopteryx, were ) L. H4 b+ Y, b+ K3 b6 A3 Q
fossilized. And not only were the bones preserved in these skeletons, but so also % @1 z6 b& W, y. ~) _1 Q
were imprints of the feathers. If the indications of feathers had not been preserved in + {; Z: b" g+ `" s# l1 t
(10)association with Archaeopteryx, it is likely that these fossils would have been
! a9 D" i$ l+ X& K8 e* {4 {classified among the dinosaurs, for they show numerous theropod characteristics. 7 g/ P) D3 X, c5 l
Archaeopteryx were animals about the size of a crow, with an archeosaurian type of % Q7 E, Y: Z+ m! u/ _
skull, a long neck, a compact body balanced on a pair of strong hind limbs, and a
& y' r* E% S( D8 ^! Wlong tail. The forelimbs were enlarged and obviously functioned as wings.
q* F$ f+ i" q# o3 r5 z4 d(15) Modern birds, who are the descendants of these early birds, are highly
& t: r A- j) e9 s1 H4 `% uorganized animals, with a constant body temperature and a very high rate of
4 T3 Q3 p/ ]" i5 ~2 U( |metabolism. In addition, they are remarkable for having evolved extraordinarily ! B+ o% j( _+ c' p$ c8 N+ I' x
complex behavior patterns such as those of nesting and song, and the habit among ! r- p( D" ?6 a' `
many species of making long migrations from one continent to another and back
" s( f& ?, ^7 }1 {7 \& y(20)each year. & C5 L% n% Z6 p: ~9 d1 ^( o9 _6 }
Most birds also have very strong legs, which allows them to run or walk on the ! M3 Y9 v: O' T/ y
ground as well as to fly in the air. Indeed, some of the waterbirds, such as ducks and ( E- ~, M, I/ L3 T0 V8 o0 z3 m* d
geese, have the distinction of being able to move around proficiently in the water, on 5 P p; N! D" x% @, m9 w
land, and in the air, a range in natural locomotor ability that has never been attained
4 y( L1 k/ {3 t$ \) c9 K(25)by any other vertebrate. 9 m5 }( j1 X8 t% T v0 B
# J) t( k9 V- \
' U: b' b3 x/ O w2 K
, ^9 g+ w7 l B% r3 `1 z$ V1. According to the author, all of-the following evidence relating to the first birds was found EXCEPT * `$ Q3 O, c2 D) M
(A) nesting materials! I# k' S5 D, X4 b. H8 i
(B) four skeletons in good condition
7 A* z' C! x7 @(C) two fragmented skeletons : X+ \+ F: i# Q
(D) a single feather
6 \1 R6 I( ]5 }! i3 `9 h& C9 p8 l ) J7 x$ I5 V3 i' P, g
2. The word "preserved" in line 8 is closest in meaning to
# ^% f Q7 ~( j- R6 O9 S- s(A) confused with others
3 ^4 K# Y) C; f# }7 Z, ?(B) gradually weakened
3 G: c* Z5 d3 M% Q; m3 w+ I(C) protected from destruction 5 p. Y$ A' i+ V% G% M p2 v+ V$ j5 ]
(D) lost permanently ' G0 P0 f5 G1 u5 B: z
- q0 g* F- Y# j6 e7 B1 w( q& t3 ?
3. It can be inferred from the passage that the Archaeopteryx were classified as birds on the basis of
2 V& G( G4 ^" T W. Y9 x% H/ Q. e(A) imprints of bones
& _6 F W p! @& `+ ` f7 C(B) imprints of feathers " g2 i! r. l: W& k' d" ^, s) Z
(C) the neck structure
% d. d* @$ d. H9 j% g' O(D) skeletons |
发表于 2012-8-14 22:34:35
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