tough day是什么意思

tough day的意思是艰难的一天。例句：Today was a really tough day，but I have to congratulate Na Li because she is really grown up fastly this year and she played really well（今天确实是个艰难的日子，但是我得对李娜表示庆祝，因为她这一年来成长飞快，打得的确很好）。