$1.$ Explain the terms: critical path, critical activities.

$2.$ The following are the time estimates and the precedence relationships

of the activities in a project network:$\backslash$table$[[$Activity$,\backslash$table$[[$IMMEDIATE$],[$Predecessor$],[$Activity$]],\backslash$table$[[$time estimate$],[($weeks$)]]],[$A$,-,4],[$B$,-,7],[$C$,$A$,3],[$D$,$B$,6],[$E$,$B$,4],[$F$,$C$,7],[$G$,$E$,6],[$H$,$D$,10],[$I$,$F$,$ G$,3],[$J$,$H$,$ I,$4],[$K$,,]]$

Draw the project network diagram. Determine the critical path and the project completion time.