En los animales, el sistema circulatorio no es complemento del respiratorio ya que el intercambio de gases se realiza independientemente del transporte de sustancias. ¿Qué características tiene el sistema circulatorio de los organismos que presentan esta particularidad?

What is hydroelectric power produced by?

My question says on my assignment. read the following scenarios and decide which of the properties of life are being described. the first one is. katherine stopped on the way to school to grab some donuts. 2. because a dog cannot sweat, it has to pant in order to stay cool. 3. an elephant trun had no bone but 4,000 muscles. i have no idea what i am supposed to anwer. i can't find the answer in my notes or book that i can understand anyway

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine