【题目】I cannot __________ puzzled, for I simply cannot understand how I could have made such a stupid mistake.
A. help feel B. help but to feel
C. but to feel D. but feel
在线课程【答案】D
【解析】句意：我不禁感到迷惑，因为我一点儿也不理解我怎么犯了一个如此愚蠢的错误。cannot but表示“不得不，只好，不禁”，之后常跟不带to的动词不定式，故D项正确。