$1$a$.$ Describe the meaning subtype$-$supertype structure, and draw an example.

$1$b$.$ Describe the meaning of a weak relationship, and draw an example.

$1$c$.$ Describe the meaning of minimum cardinalities, and draw an example and state your

justification.

$1$d$.$ Describe the meaning of an identifying relationship $($namely ID$-$dependent relationship$),$

draw an example.

$1$e$.$ Describe the meaning of a recursive relationship and draw an example