[Solved] Which one of the following is helpful in the treatment of early ejaculation? A) the use of dilators B) rear entry coitus C) erotic fantasy D) the squeeze technique Birds: Warm-blooded vertebrates that are characterized by feathers, beaks, and laying hard-shelled eggs, and they have a high metabolic rate and a lightweight skeletal system. Monotremes: A group of egg-laying mammals that includes the platypus and echidnas. Marsupials: Mammals that carry and nourish their newborns in an external pouch, including species such as kangaroos, koalas, and opossums. Placentals: Mammals that nourish their developing fetus via a placenta, an organ that facilitates the exchange of nutrients, gases, and wastes between the mother and fetus.