Explain the evolution of heart in vertebrates SOMEONE HELP PLZZZ
IM RLLY NOT UNDERSTANDING THIS SO PLZ EXPLAIN WELL AND THANK YOU

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. the following chemical equation shows the combustion of ethane. balance the equation by filling in the coefficients. c2h6 + o2 → co2 + h2o

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.