单选题 Mr. Howard has committed himself ______ helping children who are disabled and those in need of help.
【正确答案】 D
【答案解析】[解析] 语法:介词
1.本题选项由介词和连词构成。
2.commit意为“献身……、专注……”,与介词to连用,因此D为正确选项。被动语态形式的be committed to-ing也经常作为考题出现。