Acid rain
caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.
Cards and envelopes are considered first class mails by Indian postal network.
Answer:
be suitable for the elderly
Explanation:
The correct answer is "source" - this is the beginning of the river. (typically in the mountains)
Mouth of a river is the "end" of the river- it's when the river joins the ocean.
A tributary is another river that ends in the main river
and the watershed is a piece of land that separates bodies of water.
