【简答题】在细菌细胞结构中,()具有保护细胞及维持细胞外形的功能;()具有控制细胞对营养物及代谢产物的吸收和交换作用;()是细胞进行生命活动,新陈代谢的场所;()是呼吸酶类的载体,细胞的能量供应站;()具有传递细胞遗传性状的作用。
【单选题】根据下面内容,回答题: 已知从某中药中通过提取和精制获得了某化学成分,该成分为无定性粉末,可溶于甲醇、乙醇中,不溶于乙醚和石油醚。对其进行各项颜色反应结果如下:醋酐一浓硫酸反应阳性、Molish反应阳性、Legal反应阳性、Keller-Kiliani反应阳性。试通过以上结果推断其化学结构。 该化合物可能为以下哪个结构类型 查看材料
【单选题】There me two maps on the wall: one is a map of China, and ______ is a map of the world.
【简答题】. According to official statistics released by the Chinese government, China is expected to run out of water around the year 2030. In its directive on water use, the State Council (国务院) has stated, “T...
【简答题】China became the 143rd member of the World Trade Organization on December 11 , 2001 , thus its 15-year wish to join the global trade body . A . having realized B . realized C . realiz...
【多选题】从某中药中提取一化合物,其Molish反应,Trim_Hill试剂及Shear试剂反应均呈阳性,遇酸碱易沉淀及颜色变化,符合此条件的化合物可能为:
【单选题】The teachers in our university has a ______ of backgrounds.