Physics
Holography is a technique of

Recording a permanent, sharp two diimensional black and white or multicolour photograph
Recording a permanent three dimensional photograph of a given single colour or a multicolour
Recording a permanent three dimensional multicolour photograph
Recording a permanent three dimensional black and white photograph

ANSWER DOWNLOAD EXAMIANS APP

Physics
It takes much longer to cook food in the hills than in the plains, because

n the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking
due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100oC and therefore water takes longer to boil
in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere

ANSWER DOWNLOAD EXAMIANS APP