Question

the spectrum of sunlight is continuous.why?

Answer 1

because photons are emmiting with the speed of 3*10^8m/sc

Answer 2

those are emission lines. They happen when light passes through a filter (such as an emission nebula). While there is quite a bit of light emitted at the hydrogen line, the vast majority is emitted due to black body radition. Hot objects emit radiaion at all frequencies.