Reall the following passage about humanoid robots and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.
Online classes have been the best possible solution for educational institutions as well as students during the pandemic. Online education or online classes were not a new concept, but online classes' prominence was seen only(18)__. The online class provides a flexible and quick learning option. Its adaptability and efficiency (19)__during the pandemic's early days. It lowers the distance between learning locations. There are a lot of advantages as well as disadvantages to online classes. It is a versatile method of learning which helps connect with people from various parts of the globe,(20)__. Students were given their comfort zone to study,(21)____. It reduced a lot of paperwork, ultimately saving mother earth. Many renowned institutions have changed (22)____to online methods because it made education more accessible.