A group of people are building a house. They have a large package of building materials that needs to be moved. A block and tackle, a type of pulley, is used to pull the material up so it can be set in the back of a truck.
The two types of crust are oceanic and continental, the lithosphere is composed of earth's crust and upper most mantle
a because its all living things
I think it's True.. ((:
http://www.chemguide.co.uk/physical/basicrates/catalyst.html
That might help ^