$[6]$ The picture below shows a cubic crystal structure. Answer the following questions.

$(1)$ What is the name of this crystal structure?

$(1)$ Simple cubic

$(2)BCC$

$(3)$FCC

$(4)$ HCP

$(2)$ Select all of the following planes that have the same planar density as the plane marked with a triangle $($blue plane$)$ in the picture below.

$(1)(100)$ plane $(2)200)$ Jlane $(3)(110)$ plane $(4)(101)$ plane $(5)(111)$ plane

$(3)$ How many tetrahedral sites are included in the unit cell of this crystal structure?