How were Robert Hooke's findings different from Schleiden's, Schwann's and Virchow's? What does that prove about discoveries in the scientific world?

In what two ways were the tang and song dynasties of china similar? they jointly built the grand canal. they were economically strong. they had weak military forces. they ruled for about 300 years. they discouraged buddhist ideas.

Which of the four varnas are soldiers placed in? a. sudra b. brahmin c. vaishya d. kshatriya

How were the economies of the northern and southern states different? how ere they the same? what factors led them to develop differently?