Online distance learning is an instructional system which connec

Online distance learning is an instructional system which connects learners with educational resources．Students work on their own at home,at work,or at school and communicate with faculty and other students by means of e-mail,electronic meetings,videoconferencing,chat rooms,instant messaging and other forms of computer-based communication．There are both advantages and disadvantages to online distance learning. There are many benefits to using online distance learning environments．Online education is available all the time,anywhere and to all people．However,there are weaknesses for some learners．The online learner only has the written text and no other face-to-face hints．This may confuse the learner and cause misunderstanding．While distance learning allows for an openness,it is also difficult because it is done by e-mail messages and writing,and therefore may take more time than face-to-face learning．Sometimes the messages can be overwhelming for many online students. Universities,colleges and schools use online distance learning environments．These are important for students who may be unable to attend classes for various reasons like illnesses or busy everyday schedules．Some learners just want to further their studies at home．They enjoy the convenience of home learning as they take regular programs or enrichment classes. Online courses keep learners very occupied at all hours of the day．There are a great many messages and other online resources to read and respond to．Most learners have regular jobs or attend regular school classes on ground as well．However,the benefits are clear．Online distance learning is becoming very popular．Some online classes have become a profitable business as they replace regular traditional means of learning. One of the good aspects of online distance learning is__.
A、speed
B、convenience
C、easy operation
D、variety of instruction
【正确答案】：B
【题目解析】：根据文章描述，在线远程学习提供了许多便利，如学生可以在家、工作地或学校自主学习，并通过电子邮件、电子会议、视频会议、聊天室、即时消息等多种形式与教师和其他学生交流。这些特点都体现了在线远程学习的便捷性。 A选项“速度”在文章中并未明确提及为在线远程学习的一个显著优点。虽然电子邮件和即时消息可能比其他形式的通信更快，但文章主要强调的是其便捷性而非速度。 C选项“操作简单”同样没有在文章中作为在线远程学习的一个主要优点来讨论。 D选项“教学方式的多样性”虽然在线远程学习确实提供了多种教学方式，但文章并没有特别强调这一点作为其主要优点。 B选项“便捷性”则贯穿文章始终，是文章讨论在线远程学习优点时的核心词汇。文章提到在线远程学习可以随时随地进行，适合因各种原因无法到校上课的学生，以及那些喜欢在家学习的学生。 因此，正确答案是B，即在线远程学习的一个好方面是它的便捷性。