下列每个句子中均有一处错误，请找出并改正。

小题1: We don’t know that we can do about it.

小题2:Could you tell me how I could get to the nearest post office?

小题3:The old man said he had joined the army in 1965.

小题4:Mary said she did not heard from her old classmate since September.

小题5: Charles asked he could use my car.

小题6:Mother asked me where I will go the next day.

小题7:Do you have a friend whom you could tell everything, like your deepest feelings and thoughts.

小题8:Don’t look at someone else paper, John. You should do it by yourself.

小题9: In order to improve your English, you can try writing an English diary every day.

小题10: The teacher gave a series of example in her lecture in order that everybody could understand.

从句式搭配的角度看，最恰当的一项是[ ]

　　在我迷惘徘徊的时候，你呼唤我：是山的儿女就应坚如磐石；在我骄傲的时候，你呼唤我：______________；在我怯懦的时候，你呼唤我：是山的儿女就应勇敢如山。

A．是山的儿女怎能居功自傲

B．是山的儿女就应虚怀若谷

C．谦虚谨慎是山的儿女的优秀品质

D．是山的儿女就不能自满自足