D.stable to slightly shrinking
The Sahel. The Sahel is a region of sub-Saharan Africa and it is also a zone of ecological transition between the Sahara to the north and the wetter savannas to the south. Sahel belt or Sahel is a tropical savanna ecoregion in Africa. Africa is the second largest continent. It has 54 sovereign countries.
Answer: A. Zidovudine (Retrovir) and emtricitabine (Emtriva)
Explanation:
Basic postexposure prophylaxis (PEP) therapy typically includes treatment with one of these combinations of pharmacologic agents:
Zidovudine (Retrovir) and emtricitabine Emtriva),
Lamivudine (Epivir) and tenofovir (Viread), or
Tenofovir (Viread) and emtricitabine (Emtriva)
If the accidental exposure is especially severe, a third agent may be included.
Answer:
the mass of the system must remain constant over time
Explanation:
In other words matters cannot be created or destroyed, the overall amount will remain the same