Please help thank u:) will mark brainliest

In what two ways were the tang and song dynasties of china similar? they jointly built the grand canal. they were economically strong. they had weak military forces. they ruled for about 300 years. they discouraged buddhist ideas.

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?

97 points what types of changes have been made in the united states to protect people from earthquakes? a. communities are no longer located along fault lines. b. building codes ensure that structures can withstand shaking. c. warnings go off when an earthquake is expected, and people evacuate the area. d. barriers have been built to prevent flooding by a tsunami.