问题补充:
. that he had wasted a lot of time, Tom decided to work hard on his study.
ARealizing
B. To realize
C. Realized
D. Having been realized
答案:
(答案→)A. Realizing
B. To realize
C. Realized
D. Having been realized
解析:句意,由于汤姆意识到自己已经浪费了很多时间,所以他决定好好学习。非谓语动词作状语,主要看非谓语动词和主语的关系。现在分词作状语多表示主动,正在进行的动作,过去分词作状语,表示被动和完成.不定式作状语通常表未来,汤姆和意识到是主谓关系,故用现在分词作状语,表原因,故选A。