When studying shrimp feeding from hydro-thermal vents at the bottom of the ocean, biologists
were surprised that the shrimps’ reproductive cycles followed seasonal patterns. Far beyond the
reach of sunlight, and with food abundant around the vents all year round, why should such
animals reproduce seasonally? The answer might involve their offspring, which in their larval form drift in the currents to colonize new vents. The larvae must feed during their trip, and their
springtime release coincides with a peak in algae raining down from surface waters. So far,
researchers have found no evidence of seasonal breeding among vent-dwelling species
that provide their offspring with yolk to sustain them or among vent-dwelling species found
in areas of the ocean with not seasonal algae blooms.
1. Which of the following best describes the function of the highlighted sentence?
A. It casts doubt on the accuracy of earlier observations of seasonal breeding among shrimp
species living near hydro-thermal vents.
B. It undermines the explanation proposed for seasonal breeding among some shrimp species
living near hydro-thermal vents.
C. It suggests that alternative theories are needed to explain seasonal breeding among shrimp
species living near hydro-thermal vents.
D. It describes the survival benefits to shrimp of mating in parts of the ocean where algae blooms rain down abundantly.
E. It supports the explanation proffered for the seasonal breeding observed among some shrimp
species living near hydro-thermal vents.
答案给的是E，但我觉得应该选A，理由是最后一句的 no evidence 就是削弱作者: 我Me是个好人 时间: 2017-8-13 01:38:14