What concentration of oxygen, in percent by volume, is considered normal and safe to work in? Group of answer choices Less than 6 6 to 16 19.5 to 21.5 More than 23.5

Which one of the following faults cause the coffee in a brewer to keep boiling after the brewing cycle is finished? a. an open circuit in the heating element b. a short circuit at the terminals c. welded contacts on the thermostat d. a leak around the gasket