When a drop of oil is placed on water surface, it spreads to form a circular path. Explain​

When cell phones were first entering the market, they were relatively large and reception was undependable. all cell phones were essentially the same. but as the technology developed, many competitors entered, introducing features unique to their phones. today, cell phones are only a small fraction of the size and weight of their predecessors. consumers can buy cell phones with color screens, cameras, internet access, daily planners, or voice activation (and any combination of these features). the history of the cell phone demonstrates what marketing trend?

The former chairman of the federal reserve, alan greenspan, used the term "irrational exuberance" in 1996 to describe the high levels of optimism among stock market investors at the time. stock market indexes such as the s& p composite price index were at an all-time high. some commentators believed that the fed should intervene to slow the expansion of the economy. why would central banks want to clamp down when the economy is growing? a. to block the formation of unsustainable speculative asset bubbles. b. to curtail excessive profits in the banking system. c. to prevent inflationary forces from gathering momentum. d. all of the above. e. a and c only.

Upon completion of the northwest-corner rule, which source-destination cell is guaranteed to be occupied? a. top-leftb. the cell with the lowest shipping costc. bottom-leftd. top-righte. bottom-right