The source of energy shown in the image is (renewable, non renewable, polluting) a drawback of building a dam is that (it will destroy ecosystems, it requires fossil fuels, it won’t be useful for irrigation)

First blank: renewable

Second blank: destroy ecosystems

Explanation:

Dams are man-made structures that are used to store water for multiple purposes like irrigation, supplying water to an area and power generation. They are also used as a flood control measure.

However, as it is a man-made structure, it can also alter natural habitats and ecosystems. Dams collect water, which means it floods a large area, destroying the ecosystem that used to exist. Also, dams also disturb the natural flow of the river, which many animals and plants rely on. This can be harmful to them.

The correct answer will be option- B.

Explanation:

The timeline of human evolution has been predicted and explained on the basis of the fossils. The age of the fossils helps determine when the different ancestor of the modern humans existed.

The modern human evolution started around 3.85 and 2.95 million years ago in Eastern Africa where the fossils of the Australopithecus afarensis were found.

They showed characters of both humans and apes and were evolved to Homo erectus which exhibited the characters of humans like elonagated legs and shorter arms. They evolved around 2 million years ago.

Later they evolved for the adaptations to living in the ice age with less height but more muscularity.  They were called Homo neanderthelensis which were our closest ancestors which became extinct.

Thus, Option-B is the correct answers.