section a-a a-a

in rear of a signal

in advance of a signal

Range of a signal

A-A-A conjugation structure

S-A(A-A) missile

A.A.A.

a bull in a china shop

A contingent plan of a fire in hospital

A fire in a building

A in terface

a picture-in-a-picture option

a round peg in a square hole

a sound mind in a sound body

a special teacher who at the same time as a teacher in charge of a class

a square peg in a round hole

a storm in a teacup

a teacher in charge of a class

a tempest in a barrel