Gracie squeezed some grapes and kept the juice in a vessel for 5 days at room temperature. on the fifth day she found that the juice tasted sour and appeared frothy.
what caused this change?

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

14 days is the half-life of phosphorus-32