Q: To prevent contamination due to back pressure, many health regulatory regimes require an air gap or mechanical backflow prevention assembly between the delivery point of mains water and local storage or use. Where submerged mains inflow is permitted, a backflow prevention assembly is required, which protects the potable water system from contamination hazards. A check valve is a basic form of backflow prevention, but often more complex devices are required because check valves are not considered to be reliable, when compared to more sophisticated devices with redundancies and reduced-pressure zones.
Can we conclude that is a check valve the same as a backflow preventer?
A: yes

Q: Bermuda is a group of low-forming volcanoes in the Atlantic Ocean, near the western edge of the Sargasso Sea, roughly 578 nautical miles (1,070 km; 665 mi) east-southeast of Cape Hatteras on the Outer Banks of North Carolina and about 594 nautical miles (1,100 km; 684 mi) southeast of Martha's Vineyard of Massachusetts. It is 898 nautical miles (1,663 km; 1,033 mi) northeast of Miami, Florida, and 667 nautical miles (1,235 km; 768 mi) from Cape Sable Island, in Nova Scotia, Canada. The islands lie due east of Fripp Island, South Carolina, west-northwest of Cape Verde, southeast of New York City, New York, north-northwest of Brazil and 1,759 km (1,093 mi) north of Cuba.
Can we conclude that is bermuda off the coast of south carolina?
A: yes

Q: When a traffic stop is made, a warning issued by the officer is a statement that the motorist has committed some offense, but is being spared the actual citation. Officers use their own discretion whether to issue a citation or warning. The motorist may receive the warning either verbally or written, but will not be charged with the offense, will not have to pay a fine, and will not receive any points. Depending on the laws of the jurisdiction, the warning may or may not appear on records visible to officers, which, if it does, could result in another stop within a fixed period of time leading to an actual citation, or in some cases, the motorist may be charged with both offenses.
Can we conclude that do you have to pay for a warning ticket?
A: no

Q: In statistics, many statistical tests calculate correlations between variables and when two variables are found to be correlated, it is tempting to assume that this shows that one variable causes the other. That ''correlation proves causation,'' is considered a questionable cause logical fallacy when two events occurring together are taken to have established a cause-and-effect relationship. This fallacy is also known as cum hoc ergo propter hoc, Latin for ''with this, therefore because of this,'' and ''false cause.'' A similar fallacy, that an event that followed another was necessarily a consequence of the first event, is the post hoc ergo propter hoc (Latin for ''after this, therefore because of this.'') fallacy.
Can we conclude that does a positive correlation indicate a casual link?
A:
no