当你不明确它是否是最核心的研究因素,你可以通过研究假设去测量与结果息息相关的那一个因变量. Products and services make loads of contributions to output, predominantly by their immediate contribution to whole output and last demand from customers, but to some extent also by way of their oblique contribution by other sectors. Nonetheless, expert services are more independent from other sec... https://essayv.com/blog/theoretical-framework怎么写/