In this paper, professional and academic theory, the combination of quantitative and qualitative methods, through the long and Synchronic comparison, draw useful conclusions academic.

本文采用专业与学术理论相结合、定量与定性相结合的方法，通过历时与共时比较，得出有益的学术结论。

youdao

He predicted that policy makers would not be able to draw useful conclusions from the work.

CNN: Study links gun laws and lower gun mortality