Answer:
Keeping lakes and rivers free of pollution.
Explanation:
The correct answer is - A. Devonian.
The Devonian is one of the seven periods of the Paleozoic Era. It lasted for 50 million years, from 410 million years ago until 360 million years ago. It is the period in which the first insects evolved, the first seeded plants, as well as the first land vertebrates. This period came after the Silurian period, and was followed by the Mississippian period.
Answer:
1923
i searched it up and it said 1923 on wikipedia
Answer:
Overlay is a GIS operation that superimposes multiple data sets (representing different themes) together for the purpose of identifying relationships between them.[2]. An overlay creates a composite map by combining the geometry and attributes of the input data sets. Tools are available in most GIS software for overlaying both Vector or raster data.
Explanation:
Before the use of computers, a similar effect was develioped by Ian McHarg and others by drawing maps of the same area at the same scale on clear plastic and actually laying them on top of each other.
