你漏给了个动词decide吧
应该是He can't decide what to take to his friend's birthday.这么神~可不可以再问一下Visiting museums is a great way to learn about different cultures.Visiting museums is a great way __ __ about different cultures.中间是填 to know 的么？谢谢~神的话先采纳，记住，按规则做事是种美德，有新问题不能追问要重新提问