Tom’s decided to devote all he could his English before going abroad.A. to improvingB. ha

问题补充：

Tom’s decided to devote all he could his English before going abroad.

A. to improving

B. have improved

C. to improve

D. improve

答案：

(答案→)A. to improving

B. have improved

C. to improve

D. improve

解析：句意：汤姆决定在出国前专注于他所有的时间来提高他的英语。Devote vt.把……奉献（给），把……专用（于）; 奉献; devote sth to (doing) sth 把时间(钱，精力等)献给某事物。所以选A。