新GRE小短文阅读练习题七

会计考友

7   During the day in Lake Constance, the zooplankton  D.  hyalina departs
, P# o* N/ F$ p5 |: D, T for the depths where food is scarce and the water cold.   D.  galeata
remains near the warm surface where food is abundant.  Even though
8 \6 O- l6 X, W4 D: P5 V D. galeata grows and reproduces much faster, its population is often
8 _( l5 G( g) W4 V5 P outnumbered byD. hyalina.
& k% P  U' E# b" f$ l
- L0 d$ n7 G2 ^# Y Which of the following, if true, most helps to resolve the apparent
paradox?

       The number of species of zooplankton living at the bottom of the
* k' J0 P4 E3 Q5 d        lake is  twice that of species living at the surface.  
4 ]. R4 [. H5 G, d8 |       Predators of zooplankton, such as whitefish and perch, live and
: ]4 c2 }. {0 F: }        feed near the surface of the lake during the day.  
" v4 t+ f- O( K       In order to make the most of scarce food resources,  D.  hyalina
        matures more slowly than  D.  galeata .  
! w* F+ x/ |( Y/ b0 l: c! I       D.  galeata  clusters under vegetation during the hotest part of
        the day to avoid the Sun's rays.  
       D.  galeata  produces    twice as many offspring per individual in
) Q6 J, H" x+ `$ m8 X7 e8 r/ a        any given period of time as does    D. hyalina.