When Hitler continued his aggression, Chamberlain pledged Britain to defend Poland's independence if the latter were attacked, an alliance that brought Britain into war when Germany attacked Poland in 1939.
FIND OUT MORE. The Earth is covered in a layer of solid rock called the crust. Rocks are either SEDIMENTARY, IGNEOUS, or METAMORPHIC. Almost all rocks made of minerals, but different rocks contain different mixtures of minerals.Granite, for example, consists of quartz, feldspar, and mica.IND OUT MORE. The Earth is covered in a layer of solid rock called the crust. Rocks are either SEDIMENTARY, IGNEOUS, or METAMORPHIC. Almost all rocks made of minerals, but different rocks contain different mixtures of minerals.
The outer part of the Earth, the crust, consists of the lightest rock. The lightest rocks form the continents, which are made mostly of the rock granite. Most of the granite on the continents has, over millions of years, been broken down, transported, and deposited into sedimentary rock.