What evidence showed that Mohenjodaro had an advanced sewer system?

Why have the aztec ruins in mexico city not been dug up?

An object weighs 40n in air , weighs 20n when submerged jn water and 30n submerged in a liquid of unknown density .what is the density of the liquid?

Which action best represents the policy of appeasement followed by britain and france prior to the start of world war ii? (a)allowing hitler to annex the sudetenland as part of the munich agreement (b)signing the nazi-soviet pact binding hitler and stalin to peaceful relations (c)sending troops to fight with the liberals during the spanish civil war (d)forbidding the sale of arms to any nation at war