Answer:
Mass and density
Explanation:
Density of an object is defined as its mass per unit volume. Mathematically, the relation is given by :

m = mass and V = volume
If we know the density of the Eraser and its mass, we can easily find its volume. Hence, the two tools are mass and density.
Answer:
Abraham, Isaac, and Jacob–The very first work God achieves for the salvation in the last days is to gather all the 12 tribes of Israel, which represents 12 sons of Jacob. In the last day, spiritual Jacob would appear as Holy Spirit and gather all the 12 tribes of God’s people to give them salvation.
Nationalism and imperialism encouraged each nation to pursue it's own in complete for power