A指的是如何是买,如果是how to choose就对了,B don't know 后面不能直接加to,一般都会加how to, what to ,where
I want to know where can I buy a magazine.
I don't know where to go 或 I don't know where I can go.
i can't decide where to go. i have no idea where to go . i don't know where to g
Buying magazines
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