Every country has its own culture. Even though each country uses doors，doors may have   different functions and purposes 小题1:___________ lead to cultural differences.

When I first came to America，I noticed that

a public building had two different doors and 小题2:___________ had distinct functions. You have to push the door with the word “PUSH” to go out of the building and to pull the door小题3:_________ the word “PULL” to enter  the building. This was new to me, 小题4:_________ we use the same door in South Korea. For quite a few times I failed 小题5:_________ (go )out of a shopping centre and was embarrassed. The way of using school bus doors was also strange to me. I used to take 小题6:__________ school bus to classes.

The school decided that when the driver opened both the front and back doors，students who 小题7:___________off the bus should get off first，and students who were getting on should get on later.

In South Korea, we do not need to wait for people to get 小题8:_________. One morning, I hurried to the bus, and when the bus doors opened, I 小题9:_____________(conscious) tried to get on the school bus through the front door. All the students around looked at me, I was totally embarrassed, and 小题10:___________ face went red. 

中国古代经纪人员的行业组织最早可以追溯到( )朝。

A．隋

B．唐

C．宋

D．元