a rocket launched 200 kilometers in 40 seconds what is the avarage spped of the rocket in kilometers per hour?

In which way are mercury and venus similar? they both rotate from east to west. they are both small and rocky. they both have thick atmospheres. they both are similar to earth in structure.

What are antigens and antibodies? how are they involved in the body’s response to incompatible blood?

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above