How do I call the constructor of a parent class?

If I have something like

abstract class parent {
  public parent(string mom, string dad) {...}
}

public class child : parent {
  //how do I cal the constructor of parent?
}

abstract class parent {
  public parent(string mom, string dad) {...}
}

public class child : parent {
  //how do I cal the constructor of parent?
}

All of the tutorials i've found only talk about inheriting a class.