It’s their duty for the soldiers our country our enemies.
A. to prevent; from
B. to keep; from
C. to protect; from
D. to defend; with
网友回答
A. to prevent; from
B. to keep; from
(答案→)C. to protect; from
D. to defend; with
解析：不定式做主语和固定词组。在本句中it是形式主语，真正的主语是后面的不定式短语。固定词组protect sb from sth保护某人不受…的伤害；prevent sb from doing sth阻止某人做某事；句意：对于士兵们来说，保护我们的国家不受敌人的伤害是他们的责任。根据句意说明C项正确。