Reading Comprehension
试题详情
题目：
The primary purpose of the passage is to
选项:
A、compare the adaptive responses of several species of columnar cacti in the Sonoran Desert with those in the arid tropical regions of southern Mexico
B、discuss some of the possible causes of the relatively low abundance of migratory nectar-feeding bats in the Sonoran Desert
C、provide a possible explanation for a particular evolutionary change in certain species of columnar cacti in the Sonoran Desert
D、present recent findings that challenge a particular theory as to why several species of columnar cacti in the Sonoran Desert have expanded their range of pollinators
E、compare the effectiveness of nocturnal and diurnal pollination for several different species of columnar cacti in the Sonoran Desert
答案:
C
