Answer the following question given this paragraph: Q: Contour tillage helps slow water run-off and what process that causes topsoil loss? Choices: - water erosion - ice shelf erosion - plate tectonics - soil erosion A:
soil erosion

Answer the following question given this paragraph: The earliest vertebrates were jawless fish. They evolved about 550 million years ago. They were probably similar to modern hagfish (see Table above ). The tree diagram in Figure below summarizes how vertebrates evolved from that time forward. Q: The earliest vertebrates were jawless what? Choices: - mammals - dinosaurs - reptiles - fish A:
fish

Answer the following question given this paragraph: In other covalent bonds, electrons are shared equally. These bonds are called nonpolar covalent bonds. Neither atom attracts the shared electrons more strongly. As a result, the atoms remain neutral in charge. The oxygen (O 2 ) molecule in the Figure below has two nonpolar bonds. The two oxygen nuclei have an equal force of attraction for their four shared electrons. Q: How are electrons shared in covalent bonds? Choices: - randomly - orderly - unequally - equally A:
equally

Answer the following question given this paragraph: Electromagnetic waves vary in wavelength and frequency. Longer wavelength electromagnetic waves have lower frequencies, and shorter wavelength waves have higher frequencies. Higher frequency waves have more energy. Q: Electromagnetic waves vary in wavelength and in what property, which is lower in waves of longer wavelengths? Choices: - size - density - resonance - frequency A:
frequency