In a scientific experiment, the is the thing the experimenter deliberately changed while observing

The 5th term in a series of even number that begin 3x

Soweto was the site of one of the that swept across south africa in the late 1970s. in his effort to end apartheid, desmond tutu turned to . the united states responded to south africa’s apartheid policy in the 1980s by .

The earth is composed of three different chemical layers: core, mantle and crust. the formation of these layers was from a process called