Answer: The way to write the sentence: "The store was freezin" as an absolute frase would be: The store freezing, we need to leave it quickly. Or We need to leave quickly, the store freezing.
An absolute phrase consists on a phrase that modifies a noun in a sentence, but it is not connected to the sentence by a conjunction. It is separated with a comma only, and it could be removed from the sentence without changing the meaning of the sentence. An absolute phrase tends to contain a participial.
It is recommended to use test strips when using the Quat solution because it doesn't always come in the right concentration.
Test strips help to check this. Sometimes, the water with which the solution is being diluted already contains other chemicals which can enervate the potency of the quat. Other times, the Quat itself comes as an already weaken solutions.