Seven in a Line, Adjacent

Treat Alice and Bob as a single combined block.

Arrange the block together with the other five people, and account for the two internal orders of the block.

1. 1. Merge into a block

   Treating Alice and Bob as one unit leaves $6$ units to arrange, and the pair can be internally ordered $2$ ways.

   $$6!\times 2=1440$$

Answer: 1440