.1. Introduction： A. 如何指出当前研究的不足并有目的地引导出自己研究的重要性？ 在叙述前人成果之后，用However来引导不足，提出一种新方法或新方向。如：However, little information(little attention/little work/little data/little research)(or few studies/few investigations/few researchers/few attempts)(or no/none of these studies)has(have)been done on(focused on/attempted to/conducted/investigated/studied(with respect to)。如：Previous research (studies, records) has (have) failed to consider/ ignored/ misinterpreted/ neglected to/overestimated, unde
