How much countries are in the world???

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?

Roman builders used rows of arches in there buildings to form a curved ceiling called what

Two types of survey questions are open questions and closed questions. an open question allows for any kind of response; a closed question allows for only a fixed response. an open question and a closed question with its possible choices are given below. list the advantages and disadvantages of each question. open question: what can be done to get students to eat healthier foods? closed question: how would you get students to eat healthier foods? 1. mandatory nutrition course 2. offer only healthy foods in the cafeteria and remove unhealthy foods 3. offer more healthy foods in the cafeteria and raise the prices on unhealthy foods what are the advantages of an open question?