http://en.wikipedia.org/wiki/Physics

Talks about the introduction of Physics, Branches of Physics, Classical, Quantum and Modern Physics etc.

http://www.englishpage.com/vebpage/verbtenseintro.html

Defines a “verb tense”, gives a tutorial between active and passive verbs and exercises .In the active verb form, the thing doing the action is the subject of the sentence an the thing receiving the action is the object i.e.

The professor teaches the students
(Subject) (Active verb) (Object)

(Doing action) (recieving action)

http://www.wong-sir.com/cit/

Gives the introduction of a computer system, categories of computers, storage devices, application and system software etc.

http://en.wikipedia.org/wiki/Coastal_erosion

Gives the theory part of coastal geomorphology, features formed due to erosion, deposition, shows examples of stretches of the coastline, provides references and other external links. Watch out for all.

http://en.wikipedia.org/wiki/Developed_country

Defines what a developed country is and gives some content about developed countries in the continents like America, Asia, Europe, Oceania etc. Talks about the level of GDP, Human development index, economies, Tertiary & quaternary sectors of industry etc.