Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Ex Input:
Context: To evaluate short- and mid-term level of imbalance after vestibular schwannoma (VS) microsurgery by the transpetrosal approach, to search for factors predictive of vestibular compensation, and to determine which patient categories need a postoperative vestibular rehabilitation program. Prospective cohort study at a tertiary referral center. Between 2010 and 2011, patients aged 18 to 75 operated on for VS by transpetrosal approaches were included. VS was characterized by its size (Koos classification) and the presence or not of a cystic component. Hearing was classified according to the Gardner Robertson grading. The preoperative workup included an audiogram, computerized video nystagmography (VNG) with caloric testing, gaze study, rotatory tests, click-evoked cervical vestibular evoked myogenic potential measurements (cVEMPs), and subjective visual vertical test. Patients were asked to complete a Dizziness Handicap Inventory (DHI). Postoperatively, patients were reevaluated on D7 (clinical status), D90 (VNG and DHI), and D180 (DHI). Timing and duration of vestibular rehabilitation were also recorded. Forty-eight patients were included. Preoperatively, 77% experienced mild instability problems with a mean DHI score of 14.1 (range 4-32). Postoperatively, 71% reported stable or even improved perceived stability. Mean DHI scores were 28.1 on D90 and 19.8 on D180. Serviceable hearing, cystic transformation, normal cVEMPs, diplopia, and vestibular syndrome on D7 were found to be predictive of worse equilibrium outcome than when absent. A preoperative caloric deficit greater than 75% seemed to be a good prognostic factor. Vestibular rehabilitation was conducted in 56% of patients. Starting it early (<1 mo) seemed to be beneficial for final equilibrium outcome. VS microsurgery provides good stability results. Some preoperative parameters may be predictive of worse or improved balance recovery, as is clinical status on D7. 
 Question: Which disease can be categorized using the Koos grading system?

Ex Output:
vestibular schwannoma


Ex Input:
Context: After a tough win over the Texans, the Steelers stayed home for a game against the Colts. In the first quarter, the Colts scored first as Adam Vinatieri nailed a 31-yard field goal for a 3-0 lead. However, the Steelers took the lead later on in the quarter when Ben Roethlisberger found Markus Wheaton on an 18-yard TD pass for a 7-3 game. In the 2nd quarter, the Steelers would score again increasing their lead as Roethlisberger found Martavis Bryant on a 5-yard TD pass for a 14-3 game. This was followed by William Gay picking off Andrew Luck and returning it 33 yards for a TD as they increased their lead to 21-3. The Colts however responded as Andrew Luck threw a 21-yard TD pass to Dwayne Allen for a 21-10 game. However, the Steelers pulled away as Roethlisberger would find Antonio Brown on 2 consecutive TD passes: from 8 and 47 yards out to increase their lead at first from 28-10 to 35-10. The Colts responded with 10 straight points first being Luck who found T. Y. Hilton on a 28-yard TD Pass for a 35-17 game followed by Vinatieri kicking a 23-yard field goal before halftime to make the score 35-20. The Steelers went back to work in the 3rd quarter as Roethlisberger and Bryant hooked up again on a 2-yard TD pass to increase their lead making the score 42-20. The Colts however were able to come within 8 later on when Ahmad Bradshaw ran for a 12-yard TD followed by Luck finding Donte Moncrief on a 31-yard TD pass to make the score 42-27 and then 42-34. In the 4th quarter, it was all Steelers when a penalty was enforced on Luck in the end zone for a safety making the score 44-34. The Steelers were able to seal the game later on when Roethlisberger found Heath Miller on an 11-yard TD pass for a final score of 51-34. Roethlisberger set franchise records with 522 yards passing and six touchdowns while picking up his 100th victory in his 150th start. Roethlisberger's yardage total was the fourth highest in NFL history. He became the first player in NFL history to go over 500 yards passing twice as the Steelers won consecutive games for the first time this season. 
 Question: Which team gave up the ball in the first half?

Ex Output:
colts


Ex Input:
Context: Weathering changes solid rock into sediments. Sediments are different sizes of rock particles. Boulders are sedi- ments; so is gravel. At the other end, silt and clay are also sediments. Weathering causes rocks at the Earths surface to change form. The new minerals that form are stable at the Earths surface. It takes a long time for a rock or mountain to weather. But a road can do so much more quickly. If you live in a part of the world that has cold winters, you may only have to wait one year to see a new road start to weather (Figure Mechanical weathering breaks rock into smaller pieces. These smaller pieces are just like the bigger rock; they are just smaller! The rock has broken without changing its composition. The smaller pieces have the same minerals in the same proportions. You could use the expression a chip off the old block to describe mechanical weathering! The main agents of mechanical weathering are water, ice, and wind. Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point (Figure 9.2). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions. This is how ice wedging works. When liquid water changes into solid ice, it increases in volume. You see this when you fill an ice cube tray with water and put it in the freezer. The ice cubes go to a higher level in the tray than the water. You also may have seen this if you put a can of soda into the freezer so that it cools down quickly. If you leave the can in the freezer too long, the liquid expands so much that it bends or pops the can. (For the record, water is very unusual. Most substances get smaller when they change from a liquid to a solid.) Abrasion is another type of mechanical weathering. With abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a slope. Moving water causes abrasion it moves rocks so that they bump against one another (Figure 9.3). Strong winds cause abrasion by blasting sand against rock surfaces. Finally, the ice in glaciers cause abrasion. Pieces of rock embedded in ice at the bottom of a glacier scrape against the rock below. If you have ever collected beach glass or pebbles from a stream, you have witnessed the work of abrasion. Sometimes biological elements cause mechanical weathering. This can happen slowly. A plants roots grow into a crack in rock. As the roots grow larger, they wedge open the crack. Burrowing animals can also cause weathering. By digging for food or creating a hole to live in the animal may break apart rock. Today, human beings do a lot of mechanical weathering whenever we dig or blast into rock. This is common when we build homes, roads, and subways, or quarry stone for construction or other uses. Mechanical weathering increases the rate of chemical weathering. As rock breaks into smaller pieces, the surface area of the pieces increases. With more surfaces exposed, there are more places for chemical weathering to occur. Lets say you wanted to make some hot chocolate on a cold day. It would be hard to get a big chunk of chocolate to dissolve in your milk or hot water. Maybe you could make hot chocolate from some smaller pieces like chocolate chips, but it is much easier to add a powder to your milk. This is because the smaller the pieces are, the more surface area they have. Smaller pieces dissolve more easily. Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earths surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. Thats why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It 
 Question: If pieces of a rock flake off due to extreme temperature differences, it would be

Ex Output:

mechanical weathering