Every country has its own culture.
Even though each country uses doors. .Doors many have   21  functions and purposes which lead to  22  differences.
When I first came to America, I noticed that a public building had two different  23   and they had distiFnct 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  24  the building. This was new to me, because we use the   25  door in south Korea. For quite a few times I failed to go out of a shopping centre and was embarrassed.
The way of using school bus doors was also   26  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,       27  who were getting off the bus should get off first , and students who were getting on should get on   28  . 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  29  _tried to get on the school bus through the front door. All the students around looked at me, I was totally  30     ,and my face went red.
21. A.different     B .important        C .practical      D .unusual
22. A.national     B .embarrassing     C .cultural        D .amazing
23. A.exits       B .entrances        C .signs          D .doors
24.A.enter        B .leave          C .open          D .close
25. A.main       B .same           C .front          D .back
26.A.annoying    B .hard           C .satisfying      D .strange
27.A.parents      B .students       C .teachers        D .drivers
28.A.sooner      B .later           C .faster         D .earlier
29.A.politely     B .patiently       C .unconsciously   D .slowly
30.A.embarrassed    B.annoyed           C .unsatisfied     D .excited