In England, dogs with large, floppy ears called hounds came into existence. These dogs were favored for hunting because of their excellent sense of smell. Which statement most accurately represents the process that produced such dog breeds from the wild-type (feral) dog?A. Natural selection directed the gene mutations and reproductive success of these breeds. B. Humans noticed dogs with large, floppy ears and a great sense of smell and wanted more like them. They then bred them with similar dogs over many generations. C. Gene mutations in dogs arose spontaneously so that hounds replaced the feral dogs in the wild. D. Natural selection has resulted in the evolution of the wild-type dog into several separate species including the hounds.

Comedians like to joke that the reason we haven’t been visited by intelligent life from elsewhere in the universe is that aliens have been monitoring earth’s broadcasts of intellectually embarrassing tv programs, like gilligan’s island, fear factor, the jersey shore, and the jerry springer showand so consider us far too primitive to merit a visit. let’s check the assertion that aliens could have been receiving them. tv programs are broadcast at a frequency of about 100mhz with about 100kw of total power in 30frames per second, which emanatesroughly uniformly in all directions. assume that interstellar space transmits these broadcasts without attenuation. no matter how smart they are, aliens would require at least one photon per frame to interpret our signals. findthe number of photons per unit time per unit area reaching a receiver on a possible planet in the nearest star system, which is about 4 light-years away (a light-year is the distance light travels in a year). if aliens aimed a receiver or detector directly at earth, how big (in diameter) would it have to be to receive a photon per frame

Atwo-stage air compressor operates at steady state, compression 10m^3/min of air from 100 kpa and 300k to 1200 kpa. an intercooler between the two stages cools the air to 300k at a constant pressure of 350 kpa. the compression processes are isentropic. a) calculate the power required to run the compressor, in kw b) compare the result to the power required for isentropic compression from the same inlet state to the same final pressure.

Hydrogen and helium are both members of?