QUES: Rivers flowing over gentle slopes move more slowly. They move much more slowly than a mountain stream. These slow moving streams create different types of features than mountain streams. Slow moving water erodes the sides of their channels more than the bottom. Also, large curves in the stream form. These curves are called meanders. Meanders are caused by erosion and deposition. Remember, faster moving water causes erosion more quickly. Slower moving water erodes material more slowly. If water is moving slowly enough, the sediment being carried may settle out. This settling out, or dropping off, of sediment is deposition. The curves are called meanders because they slowly wander over the land. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake.
Do you have any questions?
MY QUESTION: What is the broad, flat area on both sides of a river called?

QUES: Living things need non-living matter as well as energy. What do you think matter is used for? One thing is to build bodies. They also need it to carry out the processes of life. Any non-living matter that living things need is called a nutrient. Carbon and nitrogen are examples of nutrients. Unlike energy, matter is recycled in ecosystems. You can see how in Figure 3.11. Decomposers release nutrients when they break down dead organisms. The nutrients are taken up by plants through their roots. The nutrients pass to primary consumers when they eat the plants. The nutrients pass to higher level consumers when they eat lower level consumers. When living things die, the cycle repeats.
Do you have any questions?
MY QUESTION: What do living things need?

QUES: You couldnt survive without your skin. It has many important functions. The main function of the skin is controlling what enters and leaves the body. It prevents the loss of too much water from the body. It also prevents bacteria and other microorganisms from entering the body. The skin helps maintain a constant body temperature. It keeps the body cool in two ways. Sweat from sweat glands in the skin evaporates to cool the body. Blood vessels in the skin dilate, or widen. This action increases blood flow to the body surface. This allows more heat to reach the surface. The heat is then able to radiate off the body. The opposite happens to retain body heat. Blood vessels in the skin constrict, or narrow. This decreases blood flow to the body surface. This reduces the amount of heat that reaches the surface. When this happens, less heat can be lost to the air.
Do you have any questions?
MY QUESTION: Whose loss from the body is prevented by the skin?

QUES: So what is gravity? A typical definition of gravity is that it is a force. It causes an attraction between two masses. According to this definition, anything that has mass exerts a force. Any object exerts gravity on other objects. It does not matter how small it is, it has gravity. The more matter an object has, the more gravity it has. Your pencil has a tiny bit of gravity, but far too little to notice. What about a planet? It would have a lot of gravity. An objects gravity exerts a pull on other objects. Friction only occurs between objects that are touching. Gravity can act between objects that are not touching. In fact, gravity can act over very long distances. Where else can you feel gravity?
Do you have any questions?
MY QUESTION:
What would keep gravity from affecting two objects?