Cross section (geometry) of Earth at right. Cross-sections are often used in anatomy to illustrate the inner structure of an organ, as shown at left. A cross-section of a tree trunk, as shown at left, reveals growth rings that can be used to find the age of the tree and the temporal properties of its environment. Cross section (geometry) In geometry and science, a cross section is the non-empty intersection of a solid body in three-dimensional space with a plane, or the analog in higher-dimensional spaces. Cutting an object into slices creates many parallel cross sections. The boundary of a cross section in
How Long Has This Been Going On? this been going on?" Many recordings omit the first verse; Louis Armstrong's instead omits the second, which more strongly presupposes a female singer. How Long Has This Been Going On? "How Long Has This Been Going On?" is a song composed by George Gershwin, with lyrics by Ira Gershwin for the musical "Funny Face" in 1928. Replaced by "He Loves and She Loves" in "Funny Face", it was eventually introduced in the musical "Rosalie" (1928) by Bobbe Arnst as Mary O'Brien. The lyrics used as first released by Gershwin started with the refrain: "As a tot, when I trotted in