Choose the correct alternative from the following : - Assertion (A) : Graphite is slippery and used as a lubricant.
Reason (R) : Graphite has free electrons.

B. BOTH A AND R ARE TRUE BUT R IS NOT THE CORRECT EXPLANATION OF A.

Choose the correct alternative from the following : - Assertion (A) : Pressure cookers are fitted with ebonite handles.
Reason (R) : Ebonite is strong.

C. A IS TRUE BUT R IS FALSE.

Choose the correct alternative from the following : - Assertion (A) : Most of the ancient civilisations grew near the rivers.
Reason (R) : The main occupation of man was agriculture.

B. BOTH A AND R ARE TRUE BUT R IS NOT THE CORRECT EXPLANATION OF A.

Choose the correct alternative from the following : - Assertion (A) : Carbohydrates provide energy to the body.
Reason (R) : Obesity is caused by excessive intake of carbohydrates.

C. A IS TRUE BUT R IS FALSE.

Choose the correct alternative from the following : - Assertion (A) : Earthworms are not good for agriculture.
Reason (R) : Earthworms break down the soil into fine particles and make it soft.

D. A IS FALSE BUT R IS TRUE.