You define the Pet class as follows:class Pet { constructor(name, breed) { this.

First blank: class Dog extends Pet {

Second blank: super(name, breed);

The correct syntax for deriving one JavaScript class from another is extends, so the derived class declaration must be class Dog extends Pet {. This creates Dog as a subclass of Pet, allowing Dog instances to inherit members defined by the Pet constructor, including name, breed, and the show() function assigned inside the parent constructor. Inside a derived class constructor, super() must be called before using this. The call super(name, breed); invokes the parent Pet constructor and passes the values required to initialize the inherited name and breed properties. Pet(name, breed); is incorrect because a class constructor cannot be invoked like a normal function. Pet.constructor(name, breed); is also incorrect because it does not call the parent constructor for the current instance. After super() runs, the Dog constructor can safely assign subclass-specific properties such as price and gender. References/topics: JavaScript classes, inheritance, extends, derived constructors, super(), custom class creation.