The statement "The total amount of water on Earth does not change." is true. All of Earth's water is recycled through the water cycle. When water evaporates, it is not gone; it is just in vapor (gaseous) form that is unseen until it condenses. Water animals drink returned to the Earth through their excretory systems; precipitation replenishes rain that has condensed and evaporated. The same water on Earth today was around when dinosaurs roamed because it is all recycled.

The stage in the water cycle where water is heated by the Sun and turns to vapor is evaporation. The water absorbs heat from the Sun's rays and slowly releases it into the atmosphere. Water changes from a liquid state to a gaseous state (vapor) and returns to the atmosphere.

All of the examples of water are shown on the map. Water vapor is an invisible gas. Some of this water vapor condenses to form clouds. The massive storm over the Southeastern United States is an accumulation of this vapor. Water can also be seen in oceans, gulfs, ponds, and lakes across the map. Water is distributed all over Earth, and this photo is just a small collection of that water.

According to the United States Geological Survey, "About 71 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water. Water also exists in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog. The vast majority of water on the Earth's surface, over 96 percent, is saline water in the oceans. The freshwater resources, such as water falling from the skies and moving into streams, rivers, lakes, and groundwater, provide people with the water they need every day to live. Even though you may only notice water on the Earth's surface, there is much more freshwater stored in the ground than there is in liquid form on the surface. Some of the water you see flowing in rivers comes from the seepage of groundwater into river beds. Water from precipitation continually seeps into the ground to recharge aquifers, while at the same time, water in the ground continually recharges rivers through seepage. Water is never sitting still. Thanks to the water cycle, our planet's water supply is constantly moving from one place to another and from one form to another." Overall there are said to be 326 million trillion gallons of water on Earth, and only 3% is fresh water. 

Based on this information and the photo, it can be determined that the surface of the Earth is mostly covered by saltwater from the oceans.

Source: https://www.usgs.gov/special-topic/water-science-school/science/how-much-water-there-earth?qt-science_center_objects=0#qt-science_center_objects

The passage informs readers that the ocean only contains about three to four percent salt, so there is not an equal amount of water and salt in the oceans. The text also mentions that 97% of Earth's water is saltwater, so the majority of water is not found in clouds. Water evaporates from the ocean, not salt, and this is explained in the passage by describing how the oceans become saltier as water evaporates. This leaves rivers contain salt as the correct statement. Rivers have tiny amounts of salt in their water that is dumped into oceans.

According to the United States Geological Survey, “About 71 percent of the Earth’s surface is water-covered, and the oceans hold about 96.5 percent of all Earth’s water. Water also exists in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and even in you and your dog. The vast majority of water on the Earth’s surface, over 96 percent, is saline water in the oceans. The freshwater resources, such as water falling from the skies and moving into streams, rivers, lakes, and groundwater, provide people with the water they need every day to live. Even though you may only notice water on the Earth’s surface, there is much more freshwater stored in the ground than there is in liquid form on the surface. Some of the water you see flowing in rivers comes from the seepage of groundwater into river beds. Water from precipitation continually seeps into the ground to recharge aquifers, while at the same time, water in the ground continually recharges rivers through seepage. Water is never sitting still. Thanks to the water cycle, our planet’s water supply is constantly moving from one place to another and from one form to another.” Overall there are said to be 326 million trillion gallons of water on Earth, and only 3% is freshwater.

Source: https://www.usgs.gov/special-topic/water-science-school/science/how-much-water-there-earth?qt-science_center_objects=0#qt-science_center_objects

The stage in the water cycle that returns water to Earth is precipitation. Depending on the weather conditions, the temperature on the Earth's surface and in the atmosphere, and the topography of the land will determine the amount and type of precipitation. Precipitation forms when the droplets in the clouds are too heavy and fall back to Earth. Rain will fall when both the atmosphere and surface temperatures are above freezing. Hail will form when there is a thunderstorm, the temperature in the atmosphere is below freezing, and the surface temperature is above freezing. Snow forms when the temperature is below freezing in the atmosphere and on the surface of Earth. Finally, sleet is formed when the temperature in the atmosphere is above freezing, and the surface temperature is below freezing.

The phase of the water cycle when the water cools and turns into droplets is condensation. Condensation is when water turns from a gaseous state (vapor) into a liquid state. When air with water vapor cools, the gaseous water turns to a liquid. If the conditions in the atmosphere are correct, the droplets will stick together and form clouds. When the droplets get too heavy to stay in the atmosphere, they will fall back to the Earth's surface. An example of condensation on a smaller, daily scale is the droplets that form on the outside of an ice-cold beverage glass. If you pour a cup of ice water and leave it to sit on a table, you will notice that the outside of the cup gets "sweaty." The "sweat" is the water vapor in the air, meeting the cold outside of the class and cooling back into a liquid state.

The statement "Water can be found on Earth in three different states of matter." is true. Water can be found on Earth's surface and atmosphere in three states of matter: solid, liquid, or gas. All three states of matter exist on Earth at the same time. There is water locked in frozen, solid ice-caps, water vapor (gas) in the air, which we can measure as humidity, and liquid water in oceans, lakes, and rivers.