A:①细胞质②细胞液③细胞器④生物膜系统⑤细胞骨架
B:①物质跨膜运输②主动运输③被动运输④自由扩散⑤易化(协助)扩散
C:①光合作用②光反应③碳反应④C3的还原⑤ATP的形成
D:①减数分裂分裂期②第一次分裂③第二次分裂④同源染色体分离⑤非同源染色体自由组合
丘吉尔在1941年6月22日发表广播演说:“俄国的灾难就是我们的灾难,也是英国的灾难,我们要给俄国和俄国人民一切可能的援助。”这表明( )
金刚石 最清洁的燃料
石墨 清除冰箱异味
氢气 用于患者急救
活性炭 自然界最硬的物质
氧气 做干电池的电极
炭黑 高温润滑剂
制作油墨
某市“全国文明村”白村果农王保收获枇杷20吨,桃子12吨.现计划租用甲、乙两种货车共8辆将这批水果全部运往外地销售,已知一辆甲种货车可装枇杷4吨和桃子1吨,一辆乙种货车可装枇杷和桃子各2吨.(1)王保如何安排甲、乙两种货车可一次性地运到销售地?有几种方案?(2)若甲种货车每辆要付运输费300元,乙种货车每辆要付运输费240元,则果农王保应选择哪种方案,使运输费最少?最少运费是多少?
Anna is a Chinese girl . She is ten . She is in London with her parents. She doesn't know much English. She can't speak English well. Sometimes her friends don't understand her .
It's Sunday morning .She is going to the zoo to see the panda . She is waiting at a bus stop .At the bus stop she asks a boy how to go to the zoo. But the boy can't understand her .Then she takes out a pen and some paper. She draw a panda on it and shows the picture to the boy .The boy smiles and then shows her the way to the zoo.