题目

Yuan Longping was a world-famous scientist. Because of his achievements, rice ________ has been increased greatly.A．populationB．contributionC．productionD．introduction 答案：【答案】C【解析】句意：袁隆平是世界著名的科学家，由于他的成就，水稻产量大大增加。考查名词辨析。population 人口；contribution贡献；production产量；introduction介绍。根据常识可知，由于袁隆平的成就，水稻产量大大增加。故选C。 的分数单位是，里面有(   )个这样的分数单位． (分数先填分子，后填分母)