单选题
The reason for the ubiquitous production of light by the microorganisms of the sea remains obscure, and suggested explanations are controversial. It has been suggested that light is a kind of
inadvertent
by-product of life in transparent organisms.
【正确答案】
D
【答案解析】解析：四个选项的意思分别是：adverse不利的；obscure模糊的，朦胧的；conspicuous显著的；negligent疏忽的，粗心大意的。句意是，海洋微生物产生无处不在的光的原因仍然不清楚，现在提出的许多解释都是有争议的。有人认为光是透明的生物体的生命中不太引人注意的副产品。所以正确答案是D选项，如The committee heard that he hadbeen negligent in his duty．(委员会听说他玩忽职守。)