_ difficult and challenging the task may be, wemust finish it on time, because there is a possibility _______our work will godown in history.

ica, may you attend the summit held in sanyathis Wednesday ——I’m afraid not. I______ with a client about his father’s will.

依次填入下列各句中横线处的词语，最恰当的一组是 （ ）①待到 于宗帽胡同，赁屋授课之后，她才始来听我的讲义。②真的猛士，将更 而前行。③何必用舞台上的 ，来掩盖生活中的无声无息。

________ I was doing the homework, my father was watching TV.

Can you tell me ______ on the Internet—OK, mum.