by the end of的用法和样例：
- Can you learn off the part by the end of the week?
- The student have all pair off by the end of term.
- The students had all paired off by the end of term.
- By the end of last week( month, year).
- He has worked off a large bank loan by the end of the year.
- By the end of the number they were all finally playing on the beat.