The little boy felt grateful the couch for his letting him the game.
A. for; join in
B. to; to join
C. to; join in
D. with; join
网友回答
A. for; join in
B. to; to join
(答案→)C. to; join in
D. with; join
解析：考查介词和词组：句意：小男孩对教练很感激，因为他让他参加比赛。Be grateful to sb，排除AD。join in参加活动，join是参加组织，let sb do让某人做…所以选C。