Lucyhadfewclosefriends.Soshedidn’tknow

問題詳情：

Lucy had few close friends. So she didn’t know _________________ about the trouble.

A. who to talk                       B. who to talk to

C. who to say                        D. what to talk

【回答】

B

知識點：非謂語動詞

題型：選擇題