We need natural resources for just about everything we do. We need them for food and clothing, for building materials and energy. We even need them to have fun. Table 2.1 gives examples of how we use natural resources. Can you think of other ways we use natural resources? Use Vehicles Resources Rubber for tires from rubber trees Steel frames and other metal parts from minerals such as iron Example iron ore Electronics Plastic cases from petroleum prod- ucts Glass screens from minerals such as lead lead ore Use Homes Resources Nails from minerals such as iron Timber from trees Example spruce timber Jewelry Gemstones such as diamonds Minerals such as silver silver ore Food Sunlight, water, and soil Minerals such as phosphorus corn seeds in soil Clothing Wool from sheep Cotton from cotton plants cotton plants Recreation Water for boating and swimming Forests for hiking and camping pine forest Some natural resources are renewable. Others are not. It depends, in part, on how we use them.

Question: "What are some natural resource sources we can use as building materials?"

Answer: "Trees"

Response: yes

Density is also an important physical property of matter. The concept of density combines what we know about an objects mass and volume. Density reflects how closely packed the particles of matter are. When particles are packed together more tightly, matter is more dense. Differences in density of matter explain many phenomena. It explains why helium balloons rise. It explains why currents such as the Gulf Stream flow through the oceans. It explains why some things float in or sink. You can see this in action by pouring vegetable oil into water. You can see a colorful demonstration in this video.

Question: "What can density explain?"

Answer: "Condensation"

Response: no

Callimaco is taken by the beauty of Lucrezia , but she is the loyal wife of Nicia , a rich and foolish lawyer . Callimaco hires the service of a shady ' fixer ' named Ligurio to aid in his quest to sleep with her . Lgurio informs Callimaco that Nicia and Lucrezia are anxious to have a child . With the fixer's help , . Callimaco masquerades as a doctor and convinces Nicia that the best way for Lucrezia to conceive a child is by her taking a potion made from the Mandrake Root . He lies and warns Nicia that the first man to sleep with Lucrezia after she has taken the potion will die within eight days . Together they devise a plan to kidnap a stranger to sleep with Lucrezia and draw out the poison . Callimaco then disguises himself and arranges to be the one who is kidnapped . Lucrezia is an honorable woman and does not at first agree to meet with the stranger . Nicia gets both Lucrezia's mother , a woman of ill repute , and her confessor Brother Timoteo , a priest of low morals , to aid in convincing Lucrezia of the necessity of the plan . After finally sleeping with Lucrezia , Callimaco confesses everything . Lucrezia gives thought to the duplicity of her husband , her mother , and her confessor , and decides that she now wants Callimaco as a lover forever . Callimaco gets what he had desired and everyone else continues to believe that each had outwitted the others .

Question: "Why does Lucrezia want Callimaco to be her lover forever?"

Answer: "She fell in love"

Response: no

As food is pushed along, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks are turned into smaller chucks. Perhaps not surprisingly, this happens when you chew your food. Once you swallow the food, your stomach also does some of this work. Chemical digestion occurs when food is broken down into useful nutrients. This is a chemical process that begins as you start to chew your food. The saliva in your mouth starts this process. Once you swallow, the acid in your stomach further breaks down food. From the stomach, the foods moves into the small intestine. In the small intestines, another set of chemicals goes to work. Are you surprised? Your small intestine, and not your stomach, does most of the work!

Question: "What is mechanical digestion?"

Answer: "A chemical reaction"

Response:
no