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.

What type of nuclear decay causes the atomic number of an element to increase by 1?

The intensity of a polarized electromagnetic wave is 12 w/m^2. part a) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=0∘ with the plane of polarization? part b) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=30∘ with the plane of polarization? part c) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=45∘ with the plane of polarization? part d) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=60∘ with the plane of polarization? part e) what will be the intensity after passing through a polarizing filter whose axis makes the angle θ=90∘ with the plane of polarization?

What do you think car designers do if the damage caused by a crash test is too severe?