A. be seen by the naked eye
B. not pass through an aluminum foil
C. be present naturally in our surroundings
D. be used as a tracer
Correct Answer: Option D
D. be used as a tracer
Do you want to study Agricultural Extension in OOU? Before you apply for the OOU…
Do you want to study Agricultural Economics in OOU? Before you apply for the OOU…
Do you want to study Cooperative and Business Management in OOU? Before you apply for…
Do you want to study Home and Hotel Management in OOU? Before you apply for…
Do you want to study Animal Production in OOU? Before you apply for the OOU…
Do you want to study Crop Production in OOU? Before you apply for the OOU…