Remember that a negative sign in the magnification value indicates that the image is real and inverted.

If an image formed behind the concave mirror, the object distance is positive but if an image is formed in front of the mirror, the image distance is negative.

(I) Actually, meet or intersect with each other. (II) Actually, converge at a point. (III) Appear to meet when they are produced in the backward direction. (IV) Appear to diverge from a point.

If salivary amylase is lacking in the saliva, the process of starch digestion will get disturb as salivary amylase helps in digestion of starch.

Simply, try to understand, when the oxygenated blood passes through the capillaries of the tissue, it gives oxygen to the body cells and takes carbon dioxide, produced during cellular respiration. Thus, it becomes richer in carbon dioxide.