You are presented with the question "What causes water to expand as it becomes ice?" and the following answer choices: - evaporation - wind - Weathering - heat - gasoline - Generating heat - friction - hydrogen bonds Now knowing that hydrogen bonds cause water to expand when it freezes and water freezes into ice when cooled, choose the best answer.
hydrogen bonds

You are presented with the question "what is electricity sometimes used to heat?" and the following answer choices: - space - hospitals - waves - direct energy - energy - Light - condensation - clouds Now knowing that electricity sometimes is used for heating buildings and hospitals incorporate most types of technical systems encountered in other types of buildings, choose the best answer.
hospitals

You are presented with the question "What can sonar be used to find?" and the following answer choices: - animals - coastlines - waves - rays or beams - submarines - water - tsunamis - patch reefs Now knowing that sonar is used to find the location of an object and submarines use sonar to find objects under the water, including other submarines, choose the best answer.
submarines