The Sun. How Old Is Our Sun? Stars like the Sun shine for nine to ten billion years The Sun is about 4.5 billion years old, judging by the age of moon.
The environment Smoke Toxic waste landfill Oil spill humo Residuos tóxicos vertedero Fuga de petróleo.
Chapter 3: Global Warming What is global warming? Is there really cause for alarm? Can anything be done about it? How can we assess the information from.
The Science of Climate Change J.C. Moore PhD Retired Physical Chemist JCMooreonline.com.
Understanding Paragraphs What is a paragraph? What is a paragraph? What is a topic? What is a main idea?
Our Atmosphere The Greenhouse Effect. The Sun The Sun provides the Earth with continuous heat and light.
