Birds have hollow bones which make them light. They also have streamlined body which help them to fly in the air.
Hollow bones to reduce body mass , feathers covering their body ,a stream lined body with powerful tail and wings with powerful muscles are the adaptations in birds for for flying.
ans is '30' because all other are following the rule of equation 2x2=4+1 = 5, 3x3=9+2=11, 4x4=16+3= 19, 5x5=25+4=29 (30 written in the series instead of 29), 6x6=36+5=41, 7x7=49+6=55
We say that everything is made up of atoms ,then this is the same with electricity which is electrically charged but atoms have no charge so what is the explanation for that?
Let's take an example of iron rod . When we apply potential energy on both the sides it causes the electrons to flow to the opposite directions which makes the negative charge of electricity.