秦王嬴政统一六国建立秦朝后，采取了一系列措施，把辽阔的疆域结成大一统的整体。西汉继承秦制，经过前期的休养生息和汉武帝的积极开拓，使秦以来的大一统局面得到进一步发展。阅读下列材料，然后问答

材料一：

材料二：“今师异道，人异论，百家殊（异）方，指意不同”，人君就无法维持统一。“诸不在六艺（六经）之科、孔子之术者，皆绝其道，勿使并进。”

——董仲舒

材料三：中国古代的中央集权制度，从产生之日起，其组织机构就具有多民族、大一统的性质，其职能就具有维护、推动、发展和形成多民族、大一统国家的历史任务。

——《凤凰网》

请回答：

我国科学家发现，亚硒酸钠能消除加速人体衰老的活性氧。亚硒酸钠中硒元素（Se）为＋4价，氧元素为－2价，则亚硒酸钠的化学式为（  ）

完形填空

    The lion is one of the most fierce (凶猛的) animals in the world. Lions can be 1 in Africa and India. Lions in Africa can live without water for about one month. Lions are also popular animals in the 2 . Almost every zoo around the world has a few lions.

    It is very 3 for people to tell male and female lions from each other. You can judge (判断) simply by their appearance. A male lion has mane while female lions do not have. Male lion 4 than female lions. A male lion usually weighs about 200 kilograms which is always heavier than a female lion. Both male and female lions have very 5 mouths. They can break the backs of other animals 6. Lions feed on other animals and one lion usually kills between ten and twenty large animals each year for 7 .

    It's unusual for lions to kill people. However, in 1898 two lions 8 and ate over one hundred people in Kenya before they were shot by a British man named P.J. Patterson. This 9 became the subject (主题) of a 1996 Hollywood movie called The Ghost and the Darkness. Now the Indian lions are endangered. It's really necessary for us to 10 the animals, or we won't see them again. Animals are our friends. It is our obligation to protect them.

Last week Maria ______ to Charlie.