问题 问答题 简答题

电泳的基本原理是什么?

答案

参考答案:

蛋白质、核酸、多糖等常以颗粒分散在溶液中,它们的净电荷取决于介质的H+浓度或与其它大分子的相互作用。带电粒子在电场中的迁移方式主要依据分子尺寸大小和形状、分子所带电荷或分子的生物学与化学特性。

阅读理解

News that Microsoft was making a $44.6 billion bid to buy Yahoo was greeted with heated discussion by many Internet users on Friday. Here are some responses:

Mark Galeassi of Kansas City, Missouri

This is the best move for both parties. Yahoo has the ideas and Microsoft has the money to finally market these ideas correctly. Microsoft and Yahoo are a perfect fit and the deal will be good for consumers.

Scott G of New Jersey

I was a Yahoo user for years along with Hotmail from Microsoft. Then Google came along: Google Earth, Google Toolbar and Gmail. Google is so innovative (创新的) with everything they do. Yahoo and Microsoft... same old story... I don’t think the merger (合并) will do anything for either company except improve the Yahoo shareholders’ bank accounts.

Michael Glosser of Estero, Florida

Right now, Yahoo offers a lot of features and tools at no cost for all different levels of Internet users. Microsoft seeks nothing but profit. Undoubtedly, they’ll do nothing other than find ways to start removing Yahoo’s formerly non-priced features. Microsoft’s greed will ruin the great thing that Yahoo currently is.

Toni Suarez of Hacienda Heights, California

Perhaps it would bring better high technology innovations to e-mail and help in researching and developing a better Internet!

Antonio Simmons of Parkville, Maryland

Microsoft purchasing Yahoo would be nothing more than an attempt from Microsoft to further impose upon the users their poor-quality software and obtain more wealth for the company. In my opinion, they will never be able to compete with Google because Yahoo and Microsoft’s current search engines are too inferior (差的) to compete. Even if combined, they still lack.

小题1:Who is in favor of the merger of Microsoft and Yahoo?

A.Antonio Simmons.

B.Michael Grosser.

C.Scott G.

D.Mark Galeassi.小题2:In the opinion of Scott G , _______.

A.the merger will contribute to Microsoft

B.Yahoo and Microsoft are lacking in innovation

C.Google is getting short of management experience

D.the merger will allow Microsoft to overtake Google小题3:Michael Grosser is afraid that _______.

A.the merger will cost Yahoo’s free features

B.the merger will lead to Microsoft’s defeating Yahoo

C.the increased competition will force Google out of the game

D.Internet users will have to buy Microsoft’s expensive software小题4:What is Antonio Simmons’ attitude towards Google?

A.Doubtful.

B.Disapproval.

C.Positive.

D.Negative.

单项选择题