AS! Which material represents continental crust?

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Which of the following statements are true chromosomes make up genes

Legumes, a type of plant, require rhizobia, a type of soil bacteria, to survive since these organisms fix nitrogen during photosynthesis. rhizobia use the legumes for food. what would most likely happen to the legume population if rhizobia suddenly became extinct?