Radon is___________?
A. germon radio
B. radio active gas
C. artificial fibre
D. an explosive
Radon is___________?
A. germon radio
B. radio active gas
C. artificial fibre
D. an explosive
A. Velocity
B. Acceleration
C. Space
D. Temperature
A. Salt
B. Chlorine
C. Carbon dioxide
D. Water
A. River water
B. Canal water
C. Sea water
D. Water in a lake
A. Pyroscope
B. Pyrometer
C. Seismograph
D. Xylometer