阅读下面的对话，根据上下文，从方框内选择恰当的选项补全对话。（有两项为多余选项）

A:   Excuse me, I am a reporter from a student magazine.      小题1:

B:   Sure, please.

A:        小题2:

B:   I am from Germany.

A:        小题3:

B:   I got here the day before yesterday.

A:   How do you like Lanzhou?

B:  I like your city very much. The people here are very friendly. But I’m still not used to the weather here. I have a sore throat today.

A:   The weather in Lanzhou is kind of dry. Drinking more water can make you feel better.

B:    Thanks for your suggestion.

A:        小题4:

B:   Of course not. I come here for watching Lanzhou International Marathon. And then I’m planning to go to Dunhuang for a tour.

A:   Great. Thank you for answering my questions.       小题5:

B:   Thank you.

借贷记账法试算平衡的理论依据是______原理。