Miners used to take canaries into coal mines primarily because ____________.
A)their singing provided companionship
B)their singing increased productivity
C)they would die of gas poisoning before miners would,providing them with a warning system
D)they ferried notes among workers on opposite sides of the mines

Question

Quizplus · Accepted Answer

Canaries are sensitive to the presence of toxic gases such as carbon monoxide, methane, and carbon dioxide. They would show symptoms of gas poisoning before humans would, thus providing miners with a warning system to evacuate the mine before they were exposed to dangerous levels of gas.

Miners Used to Take Canaries into Coal Mines Primarily Because