The difficulties of maintaining a long-term immune memory to influenza viruses are due to

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Astudent reads the following text in a science book: scientific evidence tells us that the cause of earths four seasons is the tilt of earth as it revolves around the sound the student is instructed to illustrate this information in a science book. how will the student illustrate winter in the northern hemisphere? a. earths northern hemisphere will tilt away from the sun. b. earths northern hemisphere will tilt toward the sun. c. earths orbit will be farther away than from the sun d. earths southern hemisphere will tilt away from the sun.

Diabetes is often suspected when glucose shows up in urine tests. use the model to explain how glucose could be present in urine. why do you think this symptom is especially concerning for young people?