Questions

The concept of carbon credit for manufacturers originated with the Kyoto Agreement (Protocol) of 1997.

In 1985 the physicist Wilhelm Rontgen discovered X-rays, the "X" signifying their unknown origin.He later found that the rays could pass through flesh and by using photographic plates could make images of bones inside the body. 

Before transferring the fish, the position is the man with the fish and the bucket of water. After transferring the position is: the man without the fish, but the fish inside the water in the bucket. Thus to know  whether there is any change in weight, it is enough to consider whether there is any change in weight when the fish in air is transferred into the water. The answer is there is no change as when in water though it loses weight due to upthrust of water on it, the level of water increases and exerts an equal force at the bottom.So, (c) is correct.

For undo the action or last action [Ctrl + Z] is used.

Excessive use of nitrate including manure may be responsible forthe presence of toxic substance in groundwater. Phosphate can also enter the groundwater via excessive use of fertilizers. High application rates of nitrogen containing fertilizers combined with the high-water solubility of nitrate, leads to increased runoff into surface water as well as leaching into groundwater, thereby causing groundwater pollution.

Only a fraction of the nitrogen-based fertilizers, is converted to produce and other plant matter. Nitrate pollution in groundwater comes from pit latrines, it can cause blue baby syndrome.

A rift valley is formed either due to upheaval of blocks on either sides of a fracture or due to subsidence of block between them.