Answer:
Here's how I would do it.
Explanation:
A Lewis structure shows the valence electrons surrounding the atoms.
1. Identify the central atoms
The central atoms are the least electronegative atoms (C).
I chose as my central atoms a chain of four C atoms: C-C-C-C
I stuck the most electronegative atom (O) at the end of the chain:
C-C-C-C-O
2. Complete the structure
The hydrogen atoms must be terminal. Add enough to give every atom an octet.
You should get a structure like the one below