Q.B. Write dash formulae for the following bond line formulae.
a. A bond-line structure; only the fragment 'O' survives in the extracted source text.
b. A bond-line structure; no readable content survives in the extracted source text.
c. A bond-line structure; no readable content survives in the extracted source text.
d. A bond-line structure; only the fragment 'OH' survives in the extracted source text.

Covers the full toolkit of ways an organic molecule can be drawn on paper: the full structural (dash) formula and the electron-dot (Lewis) formula, which show every atom and bond/electron explicitly; the condensed formula, which hides bond dashes and folds repeated identical groups into subscripts (e.g. CH3-CH3 for ethane); the bond-line (zig-zag) formula, which drops carbon and hydrogen symbols entirely, using a zig-zag line whose vertices and endpoints stand for carbon atoms, while heteroatoms and their attached hydrogens are always written out explicitly; and the four conventions for showing a molecule's true three-dimensional shape on flat paper -- the wedge formula (solid/dashed wedges plus plain lines for bonds coming forward, going back, or lying flat), the Fischer projection (cross) formula (used heavily in carbohydrate chemistry), the Newman projection formula (viewing straight down a C-C bond to compare rotational conformations), and the sawhorse/perspective formula (an elongated diagonal C-C bond with substituents radiating from each end).