trả lời

(5) the busiest

(6) sending

(7) to

(8) and 

giải thích

(5) các lựa chọn khác thiếu nghĩa:

  + busy: bận

  + busier: bận hơn

  + busiest: bận nhất (thiếu giới từ the cho times)

-> nên chọn the busiest.

(6) cấu trúc have the custom/tradition of + v-ing sth nghĩa là có truyền thống làm gì đó

(7) similar đi với giới từ to

(8) các lựa chọn khác thiếu hoặc sai nghĩa:

  + but: nhưng

  + or: hoặc

  + so: thì 

-> nên chọn and (và)

The end of December and the beginning of January are the busiest  times for the Japanese post office. The Japanese have a custom of sending .New year's day postcards to their friends and relatives, similar to the Western custom of sending Christmas cards. Their orginal purpose was for giving your faraway friends and relatives tidings of yourself and your immediate family. In other words, this custom existed for people to tell others whom they did not often meet that they were alive and well.