Answer:
Now a days, due to technological evolution we have modern and advanced devices than we have a 100 years ago. These devices and equipment like a DNA analyzer used in forensics have made it easier to analyze the victims DNA in no time. Not only these devices are fast and efficient but are also very accurate and help us get better and better results as the days of technological evolution are passing by....
I believe A. Nitrogen is the most abundant Gas.
Topographic maps and satellite images
Explanation:
A topographic map represents earth's surface features like land forms and structures, rivers and lakes, mountains and hills, elevations and other natural features along with man-made artificial features like cities, buildings, monuments, roads, bridges etc. These are formed by contour lines.
Topographic maps are printed with revision dates to observe the changes happening on the Earth's surface. Various land forms keeps changing due to natural and man-made causes and these needs to be updated accordingly to provide accurate details.
A satellite image provides details of the earth aerially from space. These provides details of a land form or any earth structure currently.
By comparing with older satellite images or topographic maps with the current one, the changes which occurred over time can be observed.