In which phase of cell division do the nuclear envelope and nucleolus reappear?

In which stages of mitosis are the chromosomes composed of two chromatids?

During which phase of the cell cycle do the centrosomes move towards opposite poles of the cell?

At the end of prophase, which of the following structures disperses throughout the cell?

$S$ - Statement: During anaphase,the paired chromatids separate.
$R$ - Reason: During anaphase,the spindle fibers shorten,and the centromere splits.

How many main stages are there in mitosis?