问题 问答题

我们生活的世界是由形形色色的物质组成的,你知道化学是怎么将它们分类的吗?

请你按照下面表格的要求,试一试填上你所熟悉的物质(每个空格中只填一种物质,填名称或化学式均可).

我知道

我见过

氧化物
    

答案

电离时生成的阳离子全部是H+的化合物叫酸,如硫酸等;电离时生成的阴离子全部是OH-的化合物叫碱,如氢氧化钠等;由金属离子和酸根离子组成的化合物叫盐,如氯化钠等;有两种元素组成的,其中一种元素是氧元素的化合物叫氧化物,如二氧化碳、水等.

故答案为:

 酸 碱盐  氧化物
H2SO4NaOHNaClCO2

单项选择题

Strange things have been happening to England. Still (1) from the dissolution of the empire in the years (2) World War Ⅱ, now the English find they are not even British. As the cherished "United Kingdom" breaks into its (3) parts, Scots are clearly (4) and the Welsh, Welsh. But who exactly are the English What’s left of them, with everything but the (5) half of their island taken away

Going back in time to (6) roots doesn’t help. First came the Celts, then the Romans, then Angles, Saxons, Jutes, Danes. Invasion after invasion, until the Norman Conquest. English national identity only seemed to find its (7) later, on the shifting sands of expansionism, from Elizabethan times onwards. The empire seemed to seal it. But now there’s just England, (8) of a green island in the northern seas, lashed by rain, scarred by two (9) of vicious industrialization fallen (10) dereliction, ruined, as D.H. Lawrence thought, by "the tragedy of ugliness," its abominable architecture.

Of all English institutions, the one to (11) on would surely be the pub. Shelter to Chaucer’s pilgrims, home to Falstaff and Hal, throne of felicity to Dr. Johnson, the pub- that smoky, yeasty den of jollity-is the womb of (12) , if anywhere is. Yet in the midst of this national (13) crisis, the pub, the mainstay of English life, a staff driven (14) into the sump of history, (15) as the Saxons, is suddenly dying and evolving at (16) rates. Closing at something like a rate of more than three a day, pubs have become (17) enough that for the first time since the Domesday Book, more than half the villages in England no longer have one. It’s a rare pub that still (18) , or even limps on, by being what it was (19) to be: a drinking establishment. The old (20) of a pub as a place for a "session," a lengthy, restful, increasingly tipsy evening of swigging, is all but defunct.

16()

A.equal

B.different

C.unprecedented

D.fast

问答题 简答题