*Question*
If single-celled organisms in soil convert atmospheric nitrogen into a form usable by plants, then what in soil converts atmospheric nitrogen into a form usable by plants? Answer choices: - compound of hydrogen oxygen - carbohydrates - single-celled organisms - excretory structures - peachleaf willow - members of their own species - It helps them survive - deoxyribonucleic acid
**Answer**
single-celled organisms

*Question*
If most of the universe is composed of electrons separated from atoms in stars, then most of the universe is composed of what separated from atoms in stars? Answer choices: - energy - Joules - nucleus - matter - oxygen - RNA - atoms - Energy.
**Answer**
atoms

*Question*
If asolution is formed when limestone is dissolved in ocean water, then asolution is formed when limestone is dissolved in what? Answer choices: - old caves - habitats - body water - rainfall - calcite - sandy shores - evaporation - ocean water
**Answer**
ocean water

*Question*
If fertilization of sperm produces a diploid zygote, then what produces a diploid zygote when fertilized? Answer choices: - bamboo - eggs - sperm - pollen - brain cells - lawns - embryos - h2o
**Answer**
sperm