Answer:
Calcium is a mineral that people need to build and maintain strong bones and teeth. It is also very important for other physical functions, such as muscle control and blood circulation.
Explanation:
Answer:
Probably because they just need air to being able to live and have air going in and out like carbon dioxide and getting rid of used air.
Answer:
[The recent activities of fossil fuel combustion has had adverse effects on the ozone layer]- B.
The correct answer is "limited prey is driving the bears to seek food in human settlements".
Due to the warming of the Arctic waters, the ice is melting, resulting in a serious decline of floating winter ice. Polar bears need these floating parts of ice to hunt, therefore this new situation limits the hunting opportunities of the bears. That is why polar bears are driven to human settlements to look for food.
It's a pic of 4 ..genetic engineering.. as the selected part of a specific DNA is used for some research !
