Four powerful pillars of democracy include

Nasa scientists must work together to make sure that everything is correct and accounted for when launching a shuttle. besides a physicist, what other type of scientist would be in making sure that the shuttle has the appropriate type and amount of fuel to reach its destination?

In which state was more than 100 billion tons of coal mined in 2005?

When a gasoline engine burns gasoline, what type of chemical reaction is occurring?