问题 填空题

下图是自然界中氮的循环图。请根据图回答下列问题

(1)循环过程中属于氮的固定的是______(填序号)。

(2)日本东京和美国洛杉矶都曾发生过严重的光化学烟雾事件,你认为主要是由于循环图中的过程_______________造成的。

(3)写出过程①所发生的一系列化学反应方程式____________________

(4)如果空气中同时含有较多的二氧化硫,那么,过程①引起的自然灾害是__________________。

(5)深入研究过程②的机理对人工固氮有何积极意义?_______________________

(6)过程⑦在地表上发生时,若人为地造成过程⑦过度的发生,会造成__________________,常见的人为因素有_________________,后果是______________________。

(7)根据氮在自然界中的循环,分析人类在优化氮的循环、减少与之有关的自然灾害过程中可做哪些工作? ________________________

答案

(1)①②③⑦

(2)⑧

(3)N2+O22NO、2NO+O2=2NO2、3NO2+H2O=2HNO3+NO

(4)酸雨

(5)有助于人工仿生固氮的研究

(6)水体富营养化;生活垃圾等高磷、高氮物质向水体中倾倒;水生生物过度繁殖,使水体缺氧

(7)采取可行性措施,防止空气和水污染

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How to Order

Ordering from BooksFirst is easy and safe.

Selecting Your Books

When you have found a book you would like to order, just click on Add to Basket and it will be added to your shopping basket. To make it easy to keep track of the books you’ve selected, My Shopping Basket will display your choices wherever you are on the site. When you’re ready to place your order, select View Basket.

View Basket

This is where you select the postal destination for your order, indicate whether you would like Next Day Delivery in the UK and choose gift-wrapping. You can also amend (修改) the contents of your basket by making any changes and then selecting Update Basket.

Overseas customers ordering three or more books can also request reduced airmail charges here. When you’re happy with the contents of your shopping basket, go to the Secure Checkout.

The Order Form

After you’ve completed the order form, you will receive an on-screen acknowledgment. This will be followed by an email confirming the details of your order.

We will then inform you when your order has been sent. If this is your first order, we will also inform you of your personal BooksFirst account number.

Your First Order

We’ll send you a personal account number after you have placed your first order. For following orders all you need to do is enter your personal account number and email address.

Returning Customers

If you have ordered from us before, online, by mail or telephone, you will have already owned a personal account number. You then only need to complete the full order form. Using your account number allows us to find your details from our records (they are not accessible online).

However, you do not need your BooksFirst personal account number to place an order—simply present all the required details on the order form. If you don’t have a note of your account number just Contact us so that we can supply it to you.

小题1:We can probably read this advertisement ______.

A.in a newspaper

B.in a magazine

C.on the Internet

D.on TV小题2:Yours choices will be displayed in order to ______.

A.To make it easy to keep track of the books.

B.To make sure you’ve selected a book.

C.To make an advertisement.

D.To show this is the postal destination.小题3:Which of the following is true?

A.You must put what you choose in a basket as you do in a supermarket.

B.You can find your Shopping Basket nowhere but in View Basket.

C.You will get your personal account number the third time you order..

D.You can get an account number after you place an order online小题4:The purpose of this advertisement is______.

A.to promote the sale of books

B.to show the procedure of ordering books online

C.to help readers apply for account numbers

D.to supply account numbers to readers