It used to______that sugar could decay the teeth.

A.are used to

B.used to

C.use to

D.were used to

A.used to play

B.used to playing

C.used to be playing

A.are used to

B.are used to be

C.used to be

D.used to being

A.A.is used

B.B.are used

C.C.has been used

D.D.have been used

A.is used to producing

B.is used to produce

C.used to produce

D.used to producing

A.been used for

B.got used for

C.been used to

D.got used to

A.used to take

B.is used to take

C.used to taking

A.used to be

B.would be

C.used to

D.is

A.used to live

B.used to living

C.were used to living

D.got used to live