The nature of the missions and tasks to be carried out should be considered on a case-by-case basis and should logically determine the nature of the contract, which also depended on the quality of the staff concerned.
确实，应当分别考虑到不同使命和任务的性质，这种性质应合乎逻辑地决定合同的性质，而合同的性质也取决于有关人员的素质。