a man can row a boat at 4 km per hour in still water. he rolls the boat two kilometre upstream and 2 kilometre back to a starting place in 2 hours how fast is the stream flowing

I would say since it is still water the stream flow is 0km/h. Especially because he needs the same time upstream as He does down stream.

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper.

it may be wrong but i think its a