You can be a senator only if you're a politician.

(a)  

Being a politician is not enough to make you a senator.

(a)  

A few senators are not politicians.

(a)  

Philosophers are not the only scholars.

(a)  

Every salamander is a lizard.

(a)  

Snakes are the only members of the suborder Ophidia.

(a)  

Anything that's an alligator is a reptile.

(a)  

Wherever there are snakes, there are frogs.

(a)  

Except for the vice presidents, nobody got raises.

(a)