(单选题) 20: John often attends public lectures at the University of Oxford, chiefly _______ his English.
A: to improve
B: to have improved
C: improving
D: improved
(责任编辑:admin) |
(单选题) 20: John often attends public lectures at the University of Oxford, chiefly _______ his English.
A: to improve
B: to have improved
C: improving
D: improved
(责任编辑:admin) |