Mr. Wang made up his mind to devote all he could ____ his oral English before going abroad.
A.improve
B.to improve
C.improving
D.to improving
网友回答
D解析此题中包含固定短语devote…to，其中to 为介词，后面应接定名词。动词devote后接的宾语为all，all又为先行词，后又包含一个定语从句：he could (do)。此题很容易误以为could后应接动词原形，而易选为A。