Question

the general was killed . the army fled

(suitable combination of sentences)

Answer 1

The general was killed because the army fled.

Hope it helps..

Answer 2

The general was killed and so the army fled.

Reasoning:

•    In the above sentence, the cause of the army fleeing is because of their general getting killed.
•   Lacking leadership, the army doesn’t know how to function and they flee the scene.  
•    The most suitable connecting word for the above two separate sentences or for combining these two sentences we need to use ‘and so’, because it expresses cause and effect.