Problem: 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: "Why Helium balloons rise and why materials sink or float"
Answer: yes

Problem: "The impact of her interest and work on the provision of legal services in the state of California is immeasurable," said Patricia Philips, senior of-counsel for Los Angeles' Morrison & Foerster. "Its value is felt every day by someone who would otherwise be floundering around in the legal system yet dealing with very serious problems." Zelon's public-interest work has not gone unnoticed. Several organizations that share her commitment to public service - including the National Legal Aid & Defender Association and the State Bar of California - have honored her. Two years ago, Zelon received the Laurie D. Zelon Pro Bono Award, which had been named for her one year earlier by the Law Firm Pro Bono Project, which she'd helped found. "I didn't find out until I was standing in the great hall of the Supreme Court, surrounded by 300 people who were there, that the award had been named for me and was thereafter going to be given in my name. It's very hard to believe, for anyone who knows me well, but I was actually speechless for a period," Zelon said. Zelon faced one of the greatest challenges of her legal career, she said, when her appointment to the bench forced her to switch gears from civil litigation to criminal law. "It was a steep learning curve for me," she said. "It's a whole different set of processes. The rules are different. The case law is a whole body unto itself." Attorneys praise Zelon for her thorough understanding of the law. "She's extremely well-versed in the law," Leon said. "She's very thorough in her research," Wong said. Of course, not all attorneys concur with every decision Zelon makes in court. Some city attorneys disagree with her interpretation of evidentiary statutes when Zelon puts limits on their use of hearsay testimony. But lawyers who have appeared before her say that they appreciate her intelligent interpretation of the law.

Question: "What kind of awards and honors has Zelon received?"

Answer: "The academy award"
Answer: no

Problem: The Agencies Confer When they learned a second plane had struck the World Trade Center, nearly everyone in the White House told us, they immediately knew it was not an accident. The Secret Service initiated a number of security enhancements around the White House complex. The officials who issued these orders did not know that there were additional hijacked aircraft, or that one such aircraft was en route to Washington. These measures were precautionary steps taken because of the strikes in New York. The FAA and White House Teleconferences. The FAA, the White House, and the Defense Department each initiated a multiagency teleconference before 9:30. Because none of these teleconferences-at least before 10:00- included the right officials from both the FAA and Defense Department, none succeeded in meaningfully coordinating the military and FAA response to the hijackings. At about 9:20, security personnel at FAA headquarters set up a hijacking teleconference with several agencies, including the Defense Department. The NMCC officer who participated told us that the call was monitored only periodically because the information was sporadic, it was of little value, and there were other important tasks. The FAA manager of the teleconference also remembered that the military participated only briefly before the Pentagon was hit. Both individuals agreed that the teleconference played no role in coordinating a response to the attacks of 9/11. Acting Deputy Administrator Belger was frustrated to learn later in the morning that the military had not been on the call. At the White House, the video teleconference was conducted from the Situation Room by Richard Clarke, a special assistant to the president long involved in counterterrorism. Logs indicate that it began at 9:25 and included the CIA; the FBI; the departments of State, Justice, and Defense; the FAA; and the White House shelter. The FAA and CIA joined at 9:40. The first topic addressed in the White House video teleconference-at about 9:40-was the physical security of the President, the White House, and federal agencies. Immediately thereafter it was reported that a plane had hit the Pentagon. We found no evidence that video teleconference participants had any prior information that American 77 had been hijacked and was heading directly toward Washington.

Question: "What caused the Secret Service to enhance security around the White House complex?"

Answer: "The plane attacks on the World Trade Center"
Answer:
yes