外国人常说的 a big ask 是什么意思

　　『 a big ask 』

　　难以办到的事，棘手的事

　　释义：

　　( informal) a difficult thing to achieve or deal with

　　

 

　　例句：

　　It's a pretty big ask to run faster in the second half of the race.

　　Beating the world champions is certainly a big ask for the team.