Theoretically, in vitro fertilisation could be performed by collecting the contents from a woman's fallopian tubes or uterus after natural ovulation, mixing it with sperm, and reinserting the fertilised ova into the uterus.
Upstream operations deal primarily with the exploration stages of the oil and gas industry, with upstream firms taking the first steps to first locate, test and drill for oil and gas. Later, once reserves are proven, upstream firms will extract any oil and gas from the reserve.
Best Answer: Upstream is before the catalytic converter, downstream is after. The upstream sensor(s) affect how the engine runs; the downstream sensor only tells if the catalytic converter is going bad. On some cars both sensors are the same part number, or the only difference is the length of wiring. Source(s):