Sagot :
What instrument is used to measure that the air is 21°C
A. Anemometer
B.Barometer
C.Hygrometer
D.Thermometer
When measuring the temperature of the air, it is best to use the thermometers. It is an electronic instrument that is used to accurately measure the temperature. It can either be a device or a mercury based thermometer. This instrument is handy pack and can be carried in your bag to be used in emergency situations or first aid treatment. It can also be used to measure the temperature of the body when someone has a fever.