考查事实细节。根据关键词the University of Phoenix 定位到文中首段If you doubt the popularity of the trend, you probably haven't heard of the University of Phoenix. It grants degrees entirely on the basis of online instruction.凤凰城大学的课程都是网络课程，它是一所完全基于网络的大学。由此可知凤凰城大学最显著的特征应该是所有的课程都是网络课程。02.According to the passage, distance learning is basically characterized by _______.
Aa minimum or total absence of face-to-face instruction
Ba considerable flexibility in its academic requirements
Cthe great diversity of students' academic backgrounds
Dthe casual relationship between students and professors