题干

化学与生产、生活密切相关,下列对物质的用途、解释均正确的是(   )

选项

物质

说法

解释

A

氯化镁

用惰性电极电解MgCl2溶液可冶炼Mg

Mg2+在阴极得电子生成Mg

B

氧化铝

制作耐高温材料

 Al2O3熔点很高

C

硫酸钡

 医学上用做钡餐

 Ba2+无毒

D

明矾

 作消毒剂

明矾水解产生具有吸附性的胶体粒子

A:A  

B:B  

C:C  

D:D

上一题 下一题 0.0难度 选择题 更新时间:2018-07-04 11:47:12

答案(点此获取答案解析)

B

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    The wedding tradition of “something old, something new, something borrowed and something blue” has been around for hundreds of years. The tradition of carrying or wearing one of each item is said to bring luck and fortune to the newly married couple. Have you ever stopped to think what the saying really means? What is its origin and what does each item represent?

    The original saying dates back to the Victoria times and states, “something old, something new, something borrowed, something blue and a silver sixpence in your shoe.”

    Something old   A bride may wear or carry something old to represent her continued ties to her family and her old life. Many brides wear a piece of family jewelry as their old item. Some brides wear the wedding dress worn by their mother or grandmother. In many cases, something old may also be something borrowed.

    Something new   Wearing something new is supposed to represent success and hope in the bride's new life and in her marriage. If the bride purchased her wedding dress new, it may represent her new item, but any item that is new may be used. Something “new” is usually the easiest kind to fill.

    Something borrowed   The borrowed item should be something borrowed from a friend that is happily married. It is said that their happiness will rub off on you and bring lasting happiness to your marriage. Some brides borrow an item of clothing, a piece of jewelry, a handkerchief or perhaps a beaded(带珠子的) purse.

    Something blue Wearing something blue dates back to ancient times when a blue wedding dress was worn to represent purity, fidelity and love.

    Silver sixpence   Placing a silver sixpence in the bride's left shoe is said to be a symbol of wealth. This not only refers to financial wealth, but also a wealth of happiness and joy throughout her married life. Since most brides probably don't even know what a sixpence is, this part of the tradition is not used very often in modern times. However, if a bride would like to include it in her wedding, she can purchase a silver sixpence from many companies that sell bridal supplies such as garters(袜带) and invitations.