The little boy felt grateful the coach for his letting him the game.
A. for / join in
B. to / to join in
C. with / join
D. to / join in
网友回答
A. for / join in
B. to / to join in
C. with / join
(答案→)D. to / join in
解析：对某人表示感激可用feel grateful to sb，使役动词let后跟动词原形作补语，加入比赛或具体的活动用join in，故本题选D。