▲閱讀下文，回答第 46 − 50 題
      The spread of COVID-19 has led to the closure of schools around the world and resulted in
the rise in popularity of video conferencing in virtual classrooms. However, some people may
feel concerned about the quality issues and challenges of the shift to the online environment.
      Some believe that video conferencing is a powerful and flexible tool to meet educational
goals more efficiently than before. Given the wide selection of options offered by online
learning systems, teachers can prepare suitable online resources and create an appropriate
e-learning environment to suit the needs of different types of learners, i.e., visual, audio, solo, or
interactive learners. In addition, video conferencing can improve student attendance because it
allows students to attend classes from any location of their choice, therefore lowering their
chances of missing classes.
      Others argue that teaching via video conferencing is not as simple as just seating students in
front of a webcam. Students might be easily distracted by any surrounding social media and fail
to concentrate on their screens when taking online lessons. Technical problems such as hardware
failure, network connection issues, and software bugs can interrupt the flow of online classes or
make it difficult for students to catch up with their virtual classmates. Another problem is the
lack of human interaction usually provided by face-to-face classroom settings. This minimal
interaction between students and teachers in online instruction often leads to a sense of isolation
among students.
      Video conferencing in education certainly has both advantages and disadvantages. Learning
about its negative effects and reducing them are thus very important to help teachers and
students benefit from the digital world during the COVID-19 pandemic.
【題組】46. What is the main idea of the passage?
(A) The positive and negative effects of online classes.
(B) An introduction to the online seating arrangement system.
(C) The stories about a powerful system to fight against diseases.
(D) An approach to virtual physical interactions between teachers and students.