How old is the earth and how did the scientist find out?

What is the general direction that the weather system flows in north America? Is it true that water molecules have more orderly arrangement in Ice than in liquid water? How mountain forms? Which city lies at 45 degrees north and 75 degrees west? How do hurricanes cause erosion? What was the name of the man who made the test tube holder? What is the coral reef energy pyramid? In the dictionary is Jacques cousteau listed under j or c? The stomata are located in the leafs and the chloroplasts are located in the leafs? What is the whole body annual dose limit? What is a Smaller needle shaped process medial to the mastoid process? Are chemical properties of oxygen more similar to those of sulfur or to those of fluorine? Bulbs are being replaced by CFL or LED lights because they are not good for environment Do you know CLF and LED are also made by using mercury and lead? When listening to a presentation on the harmful effects of radiation which choice will most help you understand the speakers message? How does mitotic cell division result in either growth or reproduction? What is the stupidest living organism on Earth? What is the most expensive zoo diet to feed? What term do Biologists use when they sort living things into groups? Is the gene for giving birth to twins recessive or dominant? What are two major landforms in California?