问题
选择题
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
答案
答案：D
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。