Parents are often upset when their children praise the homes of their friends and regard it as a slur on their own cooking, or cleaning, or furniture, and often are foolish enough to let the adolescents see that they are annoyed. They may even accuse them of disloyalty, or make some spiteful remark about the friends' parents. Such loss of dignity and descent into childish behaviour on the part of the adults deeply shocks the adolescents, and make them resolve that in future they will not talk to their parents about the places or people they visit. Before very long the parents will be complaining that ------------the child is -------- so secretive and never tells them anything, but they seldom realize that they have brought this on themselves .

大家好！

我想问一下这句话中为什么是The child is 在这段话中，而不是The children are ???