Once Susan had told him that if he touched his tongue to a frosty latch all the skin would tear off it .<br>Jem had promptly done it , `` just to see if it was so . ''<br>He found it was `` so , '' at the cost of a very sore tongue for several days .<br>But Jem did not grudge suffering in the interests of science .
Susan and Jem are both adults.
The text does not describe the ages of the two people involved in this "experiment", so they can be children or adults.
( z1 adult :domain ( z2 and :op ( z3 person :name ( z4 name :op "Susan" ) ) :op ( z5 person :name ( z6 name :op "Jem" ) ) :mod ( z7 both ) ) )