Question

Global warming is called (to call) the greenhouse effect because the gases above the earth make the planet comparable to a greenhouse. 2) the term «acid rain» refers to what scientists call «acid deposition». it (to cause) by destructive airborne acidic pollutants. 3) acid rain (to discover) in 1852, when the english chemist robert agnus invented the term. 4) recently, a more intensive research on the true causes of acid rain (to do) so that countries have the information they need to prevent acid rain and its dangerous effects. 5) air pollution can (to find) both outdoors and indoors. 6) every year, 14 billion pounds of sewage, sludge, and garbage (to dump) into the world’s oceans.

Answer 1

2
The "acid rain" refers to what scientists call "acid deposition". It is caused by desreuctive airborne acidic pollutants.
3
Acis rain was discovered in 1852, when English chemist Robert Agnus invented the term.
4 
Recently, a more intensive research on the true causes of acid rain has been done so that countries have the information they need to ptevent acid rai and its dangerous effects.
5
Air pollution can be found both outdoors and indoors.
6
Every year, 14 billion pounds of sewage, sludge and garbage are dumped into the wotld`s oceans.