Relying on an animal to come by is risky. A flower may have to wait a long time for the right animals to come by. What if one never passes close enough to the flower? Hoping the wind will blow is also risky for a plant. What if the wind does not blow? What if the blowing pollen does not land on another flower? The wind could even blow the pollen over the ocean where it is wasted. Giving free nectar is costly. It is not a good use of the plants energy. A plant uses a lot of energy to produce nectar. Some animals may just drink the nectar. They may not carry off any pollen in return. To improve their chances, plants evolved special traits. For example, they developed ways to hide their nectar. Only certain animals were able to get at the plants hidden nectar. These specific animals might be more likely to visit only flowers of the same species. This was also a benefit for some animals. Animals also evolved special traits to get to the nectar.

Question: "What is the purpose of hidden nectar?"

Answer: "Allow only animals likely to pollinate another plant to get to the nectar"

Response: yes

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.

Question: "What are two things matter is used for?"

Answer: "Eating plants"

Response: no

The Principals Committee had its first meeting on al Qaeda on September 4. On the day of the meeting, Clarke sent Rice an impassioned personal note. He criticized U.S. counterterrorism efforts past and present. The "real question" before the principals, he wrote, was "are we serious about dealing with the al Qida threat? Is al Qida a big deal? Decision makers should imagine themselves on a future day when the CSG has not succeeded in stopping al Qida attacks and hundreds of Americans lay dead in several countries, including the US," Clarke wrote. "What would those decision makers wish that they had done earlier? That future day could happen at any time." Clarke then turned to the Cole." The fact that the USS Cole was attacked during the last Administration does not absolve us of responding for the attack," he wrote. "Many in al Qida and the Taliban may have drawn the wrong lesson from the Cole: that they can kill Americans without there being a US response, without there being a price."

Question: "What was the main subject of the Principal Committee's meeting?"

Answer: "Terrorist threats to the US"

Response: yes

The inhabited history of the Las Vegas Valley stretches to 23,000 b.c. , when much of the area was covered by a prehistoric lake. During this period, the indigenous people lived in caves, hunting the mammals that gathered at the shoreline. The landscape of the valley changed dramatically over the next 200 centuries. The glaciers feeding the lake melted away and the lake evaporated. Fossils tell an obscure story of man's slow and sporadic development. Around 3000 b.c. , native Archaic Indians began to develop a lasting hunting and gathering culture. By this time, the valley was in much the same geographic state as it exists in today, with one exceptionthe presence of artesian springs that bubbled to the surface in several areas. These springs fed a network of streams draining through the Las Vegas Wash to the Colorado River. The areas surrounding the springs were desert oases: sprawling collections of grasses, trees, and wildlife. Many springs lay in areas that would eventually become the center of the modern Las Vegas metropolis. For about 4000 years, the Archaics thrived in a culture that included many signs of early civilization. Signs of even more advancement appeared halfway through the first millennium a.d. , when the Anasazi Indians inhabited the valley. Far more progressive than the Archaics, the Anasazi utilized such formal agricultural techniques as irrigation to assist their harvest. This permitted the Anasazi to achieve a benchmark of advanced societythe ability to live in permanent shelters year-round without need to follow wildlife. Mysteriously, the Anasazi vanished from the valley around a.d.

Question: "How did the Archaic Indians survive?"

Answer: "They were hunter gatherers, who followed wildlife, lived in caves, and showed primitive signs of civilization"

Response:
yes