TOEFL Reading: ETS-TOEFL阅读机经 - DM47M734I5E4XS0LL$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. An organism may obtain food particles from seawater when currents generated by the organism cause water to pass through its filter. B. The nutritional content of the food particles in seawater is sufficient to meet the energy demands of most planktonic animals. C. As planktonic animals require a lot of energy, they have to generate a current strong enough to bring them sufficient particles of food. D. Organisms that filter seawater to meet their nutritional needs expend a lot of energy, especially those organisms that have to create their own currents.