第一句：Do you think I would believe a story like that?
A: John, you are late again.
B: My mother was ill, and I ...
A: Do you think I would believe a story like that?
B: Well, the truth is I overslept.
第二句：It's hard to tell.
A: He promised to allow us a commission of 10%.
B: It's hard to tell.
I don't have much trust in his words.
I won't take it too seriously.
It sounds fishy to me.