Which of the following are synapomorphies of mammals?
a. hair
b. vertebral column
c. five digits
d. mammary glands
e. endothermy
f. placenta

Placenta is the correct answer for sure due to the synapomorphies that are present in the equations!

If these are the missing choices: a. to determine skin temperature, place the back of your hand against the patient's skin.b. determine body temperature by touching the patient's hands and feet.c. skin temperature will tell you very little about this patient's condition or well-being.d. the patient's skin temperature and color will likely be warm and red.my answer is: a. to determine skin temperature, place the back of your hand against the patient's skin. using the back of the hand to check for temperature rather than the palm is more effective because the back of the hand has more nerves that can feel and transmit the temperature than the palm.