PHOTOGRAPH COLLECTING gains new stature as prices rise. Price records are being set at auctions this week. At Christie's, a folio of 21 prints from Alfred Stieglitz's "Equivalents" series sold for $396,000, a single-lot record. Other works also have been exceeding price estimates. In part, prices reflect development of a market structure based on such variables as the number of prints. This information used to be poorly documented and largely anecdotal, says Beth Gates-Warren of Sotheby's. "There is finally some sort of sense in the market," she says. Corporations and museums are among the serious buyers, giving greater market stability, says Robert Persky of the Photograph Collector. "When I see prints going into the hands of institutions, I know they aren't going to come back on the market." Most in demand: classic photographs by masters such as Stieglitz and Man Ray. But much contemporary work is also fetching "a great deal of money," says Miles Barth of the International Center of Photography.

Question: "How many of Alfred Stieglitz's prints sold at a record price?"

OPTIONS:
- no
- yes

Answer: "12"

Response: no

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 are some things density explains?"

OPTIONS:
- no
- yes

Answer: "Explain many phenomena"

Response: yes

She led the way into the cheerful schoolroom, where big girls and little girls were sitting about, amusing themselves in the quiet of a long Sunday afternoon. Several of the younger children ran to her as she came in, and stood holding fast to the folds of her black habit, staring up at the strangers, while she explained the kind of instruction given, the system, and the order reigning in each department. Finally, she persuaded a little girl, only six years old, to take her dusky face out of the long flowing veil of the nun, and show how quickly she could read a sentence that Sister Winifred wrote on the blackboard. Then others were called on, and gave examples of their accomplishments in easy arithmetic and spelling. The children must have been very much bored with themselves that stormy Sunday, for they entered into the examination with a quite unnatural zest. Two of the elder girls recited, and some specimens of penmanship and composition were shown. The delicate complexion of the little nun flushed to a pretty wild-rose pink as these pupils of hers won the Colonel's old fashioned compliments.

Question: "Who led the way into the schoolroom?"

OPTIONS:
- no
- yes

Answer: "The Colonel"

Response: no

An archaeological party explore some caverns underground . Dr. Campbell and Dr. Hughes are the two leaders of the archaeological expedition , and get separated . While Dr. Hughes finds an alien corpse with a fossilized diamond , Dr. Campbell finds hieroglyphics at the cost of the party except for Hughes and himself . Two years later , Campbell and his assistant Holly are digging up the bones of Yonggary , a gargantuan dinosaur 50 times the size of a tyrannosaurus rex . Out of nowhere , people slowly are being killed around the site . While Holly is working Dr. Hughes , who has been legally dead for 2 years , goes to Holly and tells her to stop the dig . Dr. Campbell comes into the tent and sends Dr. Hughes off . Holly quits the expedition when another '' Accident '' occurs . In the town bar , Dr. Hughes finds Holly and takes her back to her Hotel room to tell her why he thinks the bones of the Dinosaur , Which he calls Yonggary , are going to bring the end of the world . After explaining , Holly and Hughes go to the site to stop Campbell but it is too late and Aliens resurrect Yonggary . After Yonggary's first appearance , the Army comes in and takes Holly and Campbell to an army base when Yonggary is dispatched by the aliens again . The army sends choppers after Yonggary , but he destroys them . Yonggary is then sent to the city and does some damage , where some jets attack him . Then Yonggary is transported to a power plant where he is attacked by rocket pack soldiers . During the fight , Hughes and Holly find out that the diamond on Yonggary's forehead is the device giving the aliens control of Yonggary .

Question: "Who was Yonggary associated with?"

OPTIONS:
- no
- yes

Answer: "Army"

Response:
no