30. The common cold is a viral disease. So is AIDS, which is caused by the Human Immunode- ficiency Virus, or HIV. Effective vaccines against these viral diseases have not been developed despite years of
research and work by dedicated scientists. One reason for this is the rapid muta- tion rate of these viruses,
leading to new surface proteins in a very short time. Return to Model 2 to speculate about how this rapid
change in the cold virus and HIV make vaccinations difficult to develop.

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.

Droughts cause very arid places such as a desert