Calculus was invented by________?
A. Al-khawarzimi
B. Pythagoras
C. Isaac newton
D. Al.kindi
Human bone does not contain_________?
A. Calcium
B. Chondroitin sulfate
C. Boron
D. Phosphate
The term PVC used in the plastic industry stands for______________?
A. Phosphavinyl chloride
B. Phosphor vanadiu chloride
C. Polyvinyl chloride
D. Polyvinyl carbobate
Oil of vitriol is_________?
A. Nitric acid
B. Hydrochloric acid
C. Phosphoric acid
D. Sulfuric acid