根据括号内的汉语提示，完成句子。
(1)She's going to buy some____ (纪念品) for her mother.
(2)____ (幸运地是)，I took an umbrella and didn't get wet.
(3)____(打嗝) loudly is not polite in public (公众的) places.
(4)Thanks for your ____ (邀请) to dinner.
(5)Tom ____ (赢) a prize in the singing competition last week.
(6)John's home is the ____ (远的) from school in his class.

某含铬Cr₂O₇^2－废水用硫亚铁铵［FeSO₄·(NH₄)₂ SO₄·6H₂O］处理，反应中铁元素和铬元素完全转化为沉淀。该沉淀干燥后得到n molFeO·Fe_yCr_xO₃。不考虑处理过程中的实际损耗，下列叙述错误的是

哥哥共买了56个气球，其中红气球和黄气球的比为4∶3，红气球有____个？黄气球有____个？

《世界巨人百传》丛书即将出版时,有人曾评价道:“每一位伟大人物,都蕴藏着一个感人至深的故事。”如果你想了解近代欧洲科学家的故事,可以选读  (    )

求下列阴影部分的面积。

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