https://online2.tingclass.net/lesson/shi0529/0002/2107/to_be_sure.mp3
https://image.tingclass.net/statics/js/2012
to be sure
的確，固然
He's a nice person, to be sure, but not very clever.
他確實(shí)是個(gè)好人，但并不很聰明。
To be sure, she is not beautiful, but she is pretty.
她長得固然不美，但很可愛。
