71行的surveyed和以下哪个词意思最相近。从68行开始,这个区别很重要因为burrow-nesting seabirds很难被观察到,所以它们不怎么被找到,survey在这里的意思是to look at or examine all of something, especially carefully,对应C的track: to search for by following evidence until found
A judge: to form an estimate or evaluation of 评估
B poll: to restrict the bounds or limits of 限制
D explore: to investigate, study, or analyze, look into sth. 探究