What are the number of birds in the world.

Por qué crees que los huevos con cáscara se llaman amnióticos?

Describe how viruses and bacteria can be used as biological weapons. what are some of the potential threats and potential benefits? do you agree with the use of viruses and bacteria as biological weapons? why or why not?

Which force diagram accurately represents a satellite in orbit around earth? image for option 1 image for option 2 image for option 3 image for option 4