Answered

Read the following sentences and answer the question that follows: All at once, pandemonium broke loose. ______________ the marching band came around the corner, dogs began barking, and the horses pulling the mayor's carriage began to run! Which word best completes the passage above?



Answer :

Hmmmm.... I would say perhaps:
Shouting, the marching band blah blah blah
BECAUSE shouting would definately cause dogs to begin barking and horses running! I would imagine pandemonium includes shouting, especially since I just watched the RDMA's. (:
Hope this helps!! 

Answer:

Simultaneously.

Explanation:

All at once, pandemonium broke loose. Simultaneously, the marching band came around the corner, dogs began barking, the horses pulling the Mayors carriage began to run. This word maintains that all the occurrence happened at the same time.