We group artworks with similar characteristics into periods or styles because it is easiest to do it that way - this way we can find common characteristics in these literary/artistic eras, and name them. For example, the Renaissance had a distinct style, which differs greatly from that of Romanticism.
<span>After ovulation, an oocyte, or egg cell, remains viable in the female body for up to 24 hours. The generally accepted lifespan in a woman's body is 12 to 24 hours for the egg and up to five days for the sperm cells. Intercourse occurring as many as five days prior to ovulation, therefore, could potentially result in pregnancy.</span>
Breaking bonds takes energy, forming bonds releases energy
If you break more bonds than you form it would be an endothermic reaction
2 - Human refuse to stop polluting.
All other three are attempting to attack the problem of pollution.
