thermometer* c = new centigrade(); thermometer* f = new fahrenheit(); displayer* cd = new displayer("centigrade"); displayer* fd = new displayer("fahrenheit"); prompter* cp = new prompter("enter centigrade value"); prompter* fp = new prompter("enter fahrenheit value"); show* sc = new show(c,cd); show* sf = new show(f,fd); update* uc = new update(c,cp); update* uf = new update(f,fp);