已知f（x）=log₃（3+x）+log₃（3-x）．

（1）求f（x）的定义域和值域；

（2）判断函数f（x）的奇偶性，并说明理由；

（3）写出函数f（x）的递增区间和递减区间．

-Could you give me an explanation ______ your keeping silent throughout the discussion?    

-Oh, terribly sorry. I had the least idea of what ________. I would have made a complete fool

  ofmyself if I had said anything.     [ ]

A. for; was discussed  

B. of; had discussed  

C. to; was being discussed  

D. with; had been discussed