The mantle is the largest layer
Answer:
1) Alfred Wegener, in the first three decades of this century, and DuToit in the 1920s and 1930s gathered evidence that the continents had moved. They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils.
Explanation:
Is this what you are looking for
If you test more than one variable in an experiment at a time than you wouldn't know what variable caused the change in the end.
