Please ring him up and _________ his plans for his summer vacation．

Please ring him up and _________ his plans for his summer vacation．

A.find

B.find out

C.discover

D.know about

答案及解析： B

解析：

句意为“请给他打个电话，问问他打算如何度暑假”。find out在此句中指“打听”。