I have a large spreadsheet that has job numbers in column A and broken up job
descriptions in column C. I'm looking for a way to concatenate the text in
the cells in column C, but it has to concatenate based on what job number is
in column A. For example:

A B C
01 Picks fruit.
01 Trims trees.
02 Does data entry.
02 Reviews records.
02 Maintains files.
03 Gives shots.
03 Monitors blood pressure.

Based on this type of information, somewhere in the spreadsheet (after each
change in column A or at the very bottom), I need lines that state the
following:

01 Picks fruit. Trims trees.
02 Does data entry. Reviews records. Maintains
files.
03 Gives shots. Monitors blood pressure.