work 最普通用词，含义广，指人们日常生活和工作中所从事的有目的的体力或脑力劳动。
task 通常指分派给的任务，也指自愿的工作，但往往是艰巨或令人厌烦的工作。
job 多用于口语，侧重指受雇用的，以谋生为目的工作，不论有无技术，也不管是零工或散工。
参考例句
1. He hope to find a better job. 他希望找到一份更好的工作。
2. He is the person for the job. 他是做这项工作的最佳人选。
3. The boss gave us a rush job. 上司派给我们一个紧急责任。
英英解释
n.
1. the principal activity in your life that you do to earn money
2. a specific piece of work required to be done as a duty or for a specific fee
3. the performance of a piece of work
4. the responsibility to do something
5. a workplace; as in the expression
6. an object worked on; a result produced by working
7. a state of difficulty that needs to be resolved
8. a damaging piece of work
9. a crime (especially a robbery)
10. a Jewish hero in the Old Testament who maintained his faith in God in spite of afflictions that test
11. any long-suffering person who withstands affliction without despairing
12. (computer science) a program application that may consist of several steps but is a single logical u
13. a book in the Old Testament containing Job's pleas to God about his afflictions and God's reply v.
1. profit privately from public office and official business
2. arranged for contracted work to be done by others
3. work occasionally
4. invest at a risk
