B. Because of the presence of hydrogen sulphide in Brass, it combines with oxygen in air and form water, evaporates. So remained sulphide is colourless in air .So Brass gets discoloured in the air.
Answer:
The digestive system is a collection of organs that work together to digest and absorb food. Digestion is the process your body uses to break the foods you eat down into molecules your body can use for energy and nutrients. The following organs work together to help your body process the foods you eat.
Mitochondria is a semi autonomous cell organelle, it is able to make its own protein because it has promiscuous DNA which has genes that have instructions to make proteins
