名师GRE阅读难句背诵实例（四）_GRE阅读

名师GRE阅读难句背诵实例（四）

　　18.Although these molecules allow radiation at visible wavelengths，where most of the energy of sunlight is concentrated，to passthrough，they absorb some of the longer-wavelength，infrared emissionsradiated from the Earths surface，radiation that would　otherwise betransmitted back into space.

　　虽然这些分子允许可见波长的辐射阳光的绝大部分能量就汇集于此不受阻挡地穿透，但它们却会吸收某些较长波长，亦即从地球表面辐射出的红外发射，这种辐射若不是二氧化碳的缘故就会被重新输送回太空。

　　19.The role those anthropologists ascribe to evolution is not ofdictating　the details of human behavior but one　of imposingconstraintsways of　feeling，thinking，and acting thatcome naturallyin archetypal situations in any culture.

　　这些人类学家所归诸于生物进化的作用，不是规定人类行为的种种细节，而是将各种限制强加于人类即在任何文化的典型情景中都会自然表露的情感、思维、以及行动方式。

　　20.A low number of algal cells in the presence of a high number ofgrazers suggested，but did not prove， that the grazers　had removed mostof the algae.

　　在存在大量食草动物的同时却只有少量的水藻花粉囊，这暗示出但没能证明食草动物已吞噬了大部分水藻。

　　21.Studies by Hargrave and Geen estimated natural community graz-ingrates by measuring feeding rates of　individual zooplankton species inthe　laboratory and then computing community grazing rates for fieldconditions　using the known population density　of grazers.