已知函数f（x）=lnx+cosx（x∈[π，2π]）．

（1）判断函数f（x）的单调性，并求函数f（x）的值域；

（2）证明方程f（x）=x-π在[π，2π]上必有一根．

The reason  　　being late for the meeting was   　 his little son fell ill this morning.

A．for, that

B．why, that

C．for, because

D．why, because