------ What did he want to know, Jim?

-------_________ I could finish writing the report.

A．When was it

B．It was when that

C．It was when

D．When it was that

设△ABC的内角A、B、C所对的边分别为a、b、c，已知a＝1，b＝2，cosC＝. (1)求△ABC的周长；    (2)求cos(A－C)的值．