What is always required to state a quantity in decibels? a. the number "20" in the equation

b. a reference value in the denominator of the ratio

c. the number "0.0002" in the numerator of the ratio

d. a reference value in the numerator of the equation

*** I put A but got it wrong! Pls help!

Cpr, or cardiopulmonary resuscitation, is a first-aid technique to save lives. it involves compressions of the patient's chest cavity. which description is the best description of the functions of chest compressions in cpr? chest compressions are done to pump the heart. chest compressions are done to strengthen the rib bones. chest compressions increase carbon dioxide inhalation. chest compressions allow the patient's muscles to wake up.

What does the number 18.9984 represent in the image?

If a force of 40 newtons moves a cart a distance of 9 meters, the work done is nm. if the same force moves the same cart three times that distance, the work done is nm.