Water snakes migrate from the river water where they were born to the depths of oceans to lay their eggs then die. When the eggs hatch, small snakes go back to rivers. How did the small snakes know that? Word limit 50

Drag the tiles to the correct boxes to complete the pairs. match the nitrogenous base of dna with its complement.

How can an organ, such as the lungs, work for multiple body systems?

Many organizations release indexes used to measure the development of the world's countries. as we learned in this lesson, these indexes measure many factors, from life expectancy to happiness. in your opinion, what are the three most important factors we can use to determine how developed a country might be? explain your answers in a few sentences.