Why do students generally perform better on multiple-choice tests than on essay tests?

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?

U.s. foreign aid incudes all the following programs excepta. humanitarian aidb. military assistancec. cycle of dependency grantsd. development aid

Lance, a hacker, stole 15,000 credit card numbers and sold them on the black mar-ket, making millions. police caught lance, and two legal actions followed, one civil and one criminal. who will be responsible for bringing the civil case? what will be the outcome if the jury believes that lance was responsible for identity thefts? who will be responsible for bringing the criminal case? what will be the outcome if the jury believes that lance stole the numbers?