The two classes were able to see the liquid mixture change into a thick and creamy ice cream with the help of an ice cream maker.
(The two classes; were; able to see the liquid mixture change into a thick and creamy ice cream with the help of an ice cream maker) (The two classes; to see; the liquid mixture change)
The two classes The two classes
were to see
able to see the liquid mixture change into a thick and creamy ice cream with the help of an ice cream maker
the liquid mixture change