在平面直角坐标系xOy中，过原点O及点A（0，2）、C（6，0）作矩形OABC，∠AOC的平分线交AB于点D．点P从点O出发，以每秒$\sqrt{2}$个单位长度的速度沿射线OD方向移动；同时点Q从点O出发，以每秒2个单位长度的速度沿x轴正方向移动．设移动时间为t秒，当t为____时，△PQB为直角三角形．

古今诗文填空。
①我们有些同学，自己不愿意被别人叫绰号，却总热衷给别人起外号，对这些同学，我们应该用孔子的“             ，            ”劝诫他们。
②我寄愁心与明月，                   。《闻王昌龄左迁龙标遥有此寄》
③《过故人庄》中描绘农村优美的自然风光的诗句是：         ，             。
④傍晚时候，上灯了，一点点黄晕的光，____________________。《春》

补全对话

（D=Darren, C= Carol）

D: Hi, Caro!  ____ 

C: Oh, hi, Darren. I'm just getting ready for the Red Nose Day concert tomorrow.

D: Oh really? Well, I'm free this afternoon.  ____ 

C:Actually, I've nearly finished. Jim and I are going to put up some ads later, though. Could you please help us with that?

D:   ____ 

C: That's wonderful! Oh, there's one more thing. Would you mind coming early tomorrow to help sell tickets at the door?

D: Not at all,  ____ 

C: Around six would be great.

D: OK. ____ 

C: Great. Thanks, Darren.

A.No problem.

B.See you then.

C.Of course not.

D.What are you doing?

E.Can I give you a hand?

F.What time shall I be there?

G.Have you finished your homework?