A：Mike promised to help us.
迈克答应帮助我们。
B：Mike? How can you trust him to help us?
迈克?你怎么能相信他会来帮助我们?
A：Why not?
为什么不能呢?
B：He is too unpredictable. He says anything that pops into his head. And then he forgets it all.
他太让人难以琢磨。他总是想起什么就说什么，可是过后一会儿就忘了一切。