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 innermost is the core, the densest of the three layers. It is a spherical mass, composed largely of metallic iron, with smaller amounts of nickel and other elements. The middle layer is the mantle, made of dense, rocky matter. The outermost layer of the earth is the crust, which is the thinnet of the three layers.