1 . I had ________ interesting experience playing ping-pong with the coach with ________ rich experience last year.

A．the; a

B．an; an

C．/; the

D．an; /

2 . Two Chinese astronauts headed outside the nation’s Tiangong space station on February 9, 2023 for   ________ seven-hour-long spacewalk, ________ first of the ongoing Shenzhou 15 mission.

A．a; the

B．the; the

C．a; a

D．the; a

3 . If however hard you study you can only score _______ above average grade, don’t worry. Your talent lies somewhere else. Not everyone is _______ A-student.

A．/; an

B．an; an

C．an; a

D．/; /

4 . He was on ________ phone when I paid ________ visit to him yesterday.

A．the; a

B．the; the

C．不填; the

D．the; 不填

5 . The year of 2021 is coming to ________ end.

A．a

B．the

C．/

D．an