According to embryology, why do fish and birds have a common ancestor?

They both have embryos with gill slits and tails.
They both have embryos with traits that eventually disappear.
They both have embryos that develop into adults.
They both have embryos that form from a fertilized egg.

According to newton's second law, when the same force is applied to two objects of different masses, a the object with greater mass will experience a great acceleration, and the object with less mass will experience an even greater acceleration, b. the object with greater mass will experience a smaller acceleration, and the object with less mass will experience a greater acceleration, c. the object with greater mass will experience a greater acceleration, and the object with less mass will experience a smaller acceleration, d. the object with greater mass will experience a small acceleration, and the object with less mass will experience an even smaller acceleration.

Aparticle initially moving east with a speed of 20.0 m/s, experiences an acceleration of 3.95 m/s, north for a time of 8.00 s. what was the speed of the particle after this acceleration, in units of m/s? give the answer as a positive number.

Individuals who live below the poverty line get seriously ill more often than those who do not what could be the hidden variable in this situation?