What are the sources of recruiters? What are their advantages and disadvantages?

The advantage of on-campus recruitment is that it is based on the school (professors, tutors and scholars from all walks of life), which is helpful for scientific research.

Disadvantages: most of them can't bear hardships, are whimsical, can't face the real society, are ambitious and unruly.

Advantages of social recruitment of "experts in the private sector"

Disadvantages are "mixed fish and dragons" and "bad habits are hard to change"

The advantages of labor market/intermediary companies meet the requirements.

Disadvantages are uneven ("smooth" and "chicken")

On-the-job personnel's relatives and friends introduce their advantages, and they have strong teamwork with relatives and friends.

The disadvantage is limited ability.