Photochemical smog generally requires the presence of

nitrogen oxides.

sunlight.

volatile organic compounds.

Explanation:

Nitrogen oxide and voc(volitale organic coumpound) or it can jut be created by nitrogen oxide and sun.

Explanation:

the reason the welfare system causes so much of a burden on its recipients is because the welfare system does not give its recipients any real tools to actually get out of poverty. the welfare system has embedded poverty deeper into society and has made it harder and harder for people to escape poverty.

in other words, it stoped the poor, and now its making it worse.

hope this . : )      

and im sorry it took so long for your question to get answered

i want to say death; parole, probation, and fines are still being used all the time.