题目内容：
完成选项 (I)Every country has its own culture.
Even though each country uses doors. Doors may have 16 functions and purposes which lead to 17 differences.
When I first came to America, I noticed that a public building had two different 18 and they had distinct functions. You have to push the door with the word "PUSH" to go out of the building and to pull the door with the word "PULL" to 19 the building. This was new to me, be-cause we use the 20 door in south Korea. For quite a few times 1 failed to go out of a shopping centre and was embarrassed.
The way of using school bus doors was also 21 to me. I used to take the school bus to classes. The school decided that when the driver opened both the front and back doors, 22 who were getting off the bus should get off first, and students who were getting on should get on 23
In south Korea, we do not need to wait for people to get off. One morning, I hurried to the bus, and when the bus doors opened, I 24 tried to get on the school bus through the front door. All the students around looked at me, I was totally 25 , and my face went red.
A．different
B．important
C．practical
D．unusual
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