题目内容
乾隆年间的税种有（）
查看答案
搜索结果不匹配？点我反馈
更多问题
The initial fund of general scientific knowledge is an invaluable asset (财产), but the young research worker should have no illusion(错觉) about how little it is compared with what he or she should acquire during succeeding years. As to the precise value of this initial fund of knowledge, this depends to a great degree on how it has been acquired and on who has been imparting(传授) it. 46)Young scientists cannot realize too soon that existing scientific knowledge is not nearly so complete, certain and unalterable as many textbooks seem to imply. The original papers of great scientists describing their discoveries and explaining their theories are never as rigid and self-confident as the resumes(摘要说明)of these discoveries and theories in textbooks by other men often suggest. Young scientists consulting these original works will find in them "it appears that", "it probably means", "it seems likely that", more than once, as expressions of elements of doubt which great men felt and honestly put on record. 47)Many statements which have appeared in textbooks as universal and absolute truths have, in their original form, been put for word as only approximately true, or true only in certain circumstances.Immediately upon starting on the first serious piece of research, a young scientist must therefore do two things. 48)The first of these should be a careful reading of original papers or books relating to the problem, written by investigators whose technique and judgement he can trust. While reading these publications in a most attentive and receptive manner, the young scientist must not fall into the error of placing in them a greater confidence than their author would wish him to do. 49)No great scientist ever wants his pupils to be mere gramophone records, faithfully reproducing his remarks, never questioning anything, never wanting to add to or subtract from what he has given them.The second thing a young scientist must do, almost but not quite simultaneously with the first, is to proceed with observations and experiments. 50)The initial observations and experiments will be failures, but they will help the development of appropriate experimental technique, and they will give a greater understanding of the literature the young scientist is studying. The first of these should be a careful reading of original papers or books relating to the problem, written by investigators whose technique and judgement he can trust
在明朝中叶，农业生产发生了一件非常重要的事件——（），对于当时的食物结构产生了重大的影响
明朝推行一条鞭法中“一”的内容是（）
扈伦四部是（）
微信支付 
支付宝支付