在以下哪个句子中，'can't help'的用法是正确的？ A. I can't help but smile. B. She can't help to laugh. C. He can't help himself to eat. D. They can't help laughing. 答案解析 本题考察'can't help'的正确用法。正确答案是D，因为'can't help'后面可以接动名词，表示无法控制的行为。A也是正确的，但D更为常见。B和C的用法不当，语法错误。 正确答案：D