23.（ ）

(单选题)The underlined word “that” in Paragraph 3 refers to ______. (单选题)According to Paragraph 1, what change does the author want t (单选题)（ ） (单选题)—Mind if I open the door now?—______. (单选题)Many netizens are impressed with the excuse given by a teach (单选题)—Is everyone here, Jonathan?—No, sir. Mille is absent. She _ (单选题)It is the teacher-and-student interaction ______ students sh (单选题)—How long do you expect it ______ before the African can kee (单选题)China is sure to further reduce the poor rural population by (单选题)Massive open online courses provide a wonderful model of ___