单项选择题
By the sixth century AD, when few Europeans could read, the Chinese ______ paper.
单项选择题 It isn't quite ______ that he will be present at meeting.
单项选择题 It is highly desirable that a new president ______ for this university.
单项选择题 It was in that small room ______ they worked hard and dreamed of better days to come.
