Why were German barbarians able to invade the Italian mainland

Which best describes the idea behind the "invisible hand"? producers decide what to make for consumers, which guides the economy. individuals seeking their own self interest benefit the economy as a whole. government sets policy for producers and consumers, which guides the economy. consumers decide what they need and want to buy, which guides the economy.

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 of the following statements most accurately describes the requirement for the documentation of minors’ assent to participate in research? parents must approve written documentation.documentation is required unless waived by an irb.to protect minors documentation is always required.federal regulations do not require the documentation of minors’ assent.