Question

pls some one solve Q4 AND Q7

Answer 1

this is a q of physics or maths

Answer 2

By changing the amount of gas in the bladder, a fish can move up or down ... A tail that tapers to a point, as in lungfishes, vertebral column extends to tip without upturning. ... Thin, overlapping scales with a smooth posterior edge that are found in some .... Cartilage skeleton fish, tough skin, good sight, smell, vibration senses