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: Coming off their divisional home win over the Cardinals, the 49ers flew to the Edward Jones Dome for a Week 2 divisional duel against their NFC West rival, the St. Louis Rams. In the first quarter, the Niners trailed early as Rams QB Marc Bulger completed a 12-yard TD pass to WR Torry Holt for the only score of the period. In the second quarter, San Francisco would tie the game up with RB Frank Gore getting a 1-yard TD run. St. Louis would take the halftime lead with kicker Jeff Wilkins getting a 29-yard field goal In the third quarter, the 49ers took the lead with Gore breaking through a gang of tacklers for a 43-yard TD run, along with the only score of the period. In the fourth quarter, the Rams retook the lead with Wiklins getting a 53-yard field goal. Fortunately, thanks to a St. Louis goof-up on special teams, the Niners took the lead with kicker Joe Nedney getting a 40-yard field goal. Near the end the game, the Rams had one last chance to win the game. Fortunately for San Francisco, Wilkins' 56-yard field goal attempt fell about a yard short of the crossbar. With the win, the 49ers improved to 2-0 for the first time since 1998. Q1 - STL - 6:04 - 12-yard TD pass from Marc Bulger to Torry Holt (Wilkins kick) (STL 7-0) Q2 - SF - 14:57 - Frank Gore 1-yard TD run (Nedney kick) (7-7) Q2 - STL - 9:04 - Jeff Wilkins 27-yard FG (STL 10-7) Q2 - STL - 1:51 - Jeff Wilkins 29-yard FG (STL 13-7) Q3 - SF - 2:43 - Frank Gore 43-yard TD run (Nedney kick) (SF 14-13) Q4 - STL - 10:04 - Jeff Wilkins 53-yard FG (STL 16-14) Q4 - SF - 3:23 - Joe Nedney 40-yard FG (SF 17-16) 
 Question: How did the 49ers take the lead in the fourth quarter?

Ex Output:
joe nedney


Ex Input:
Context: From the outside, the skin looks plain and simple, as you can see in Figure 16.5. But at a cellular level, theres nothing plain or simple about it. A single square inch of skin contains about 20 blood vessels, hundreds of sweat glands, and more than a thousand nerve endings. It also contains tens of thousands of pigment-producing cells. Clearly, there is much more to skin than meets the eye! For a dramatic introduction to the skin, watch this video: MEDIA Click image to the left or use the URL below. URL: The skin is only about 2 mm thick, or about as thick as the cover of a book. Although it is very thin, it consists of two distinct layers, called the epidermis and the dermis. You can see both layers and some of their structures in Figure 16.6. Refer to the figure as you read about the epidermis and dermis below. The epidermis is the outer layer of skin. It consists almost entirely of epithelial cells. There are no blood vessels, nerve endings, or glands in this skin layer. Nonetheless, this layer of skin is very active. It is constantly being renewed. How does this happen? 1. The cells at the bottom of the epidermis are always dividing by mitosis to form new cells. 2. The new cells gradually move up through the epidermis toward the surface of the body. As they move, they produce the tough, fibrous protein called keratin. 3. By the time the cells reach the surface, they have filled with keratin and died. On the surface, the dead cells form a protective, waterproof layer. 4. Dead cells are gradually shed from the surface of the epidermis. As they are shed, they are replaced by other dead cells that move up from below. The epidermis also contains cells called melanocytes. You can see a melanocyte in Figure 16.7. Melanocytes produce melanin. Melanin is a brown pigment that gives skin much of its color. Everyones skin has about the same number of melanocytes per square inch. However, the melanocytes of people with darker skin produce more melanin. The amount of melanin that is produced depends partly on your genes and partly on how much ultraviolet light strikes your skin. The more light you get, the more melanin your melanocytes produce. This explains why skin tans when its exposed to sunlight. The dermis is the inner layer of skin. It is made of tough connective tissue. The dermis is attached to the epidermis by fibers made of the protein collagen. The dermis is where most skin structures are located. Look again at Figure pain, pressure, and temperature. If you cut your skin and it bleeds, the cut has penetrated the dermis and damaged a blood vessel. The cut probably hurts as well because of the nerve endings in this skin layer. The dermis also contains hair follicles and two types of glands. You can see some of these structures in Figure 16.8. Hair follicles are structures where hairs originate. Each hair grows out of a follicle, passes up through the epidermis, and extends above the skin surface. Sebaceous glands are commonly called oil glands. They produce an oily substance called sebum. Sebum is secreted into hair follicles. Then it makes its way along the hair shaft to the surface of the skin. Sebum waterproofs the hair and skin and helps prevent them from drying out. Sweat glands produce the salty fluid known as sweat. Sweat contains excess water, salts, and other waste products. Each sweat gland has a duct that passes through the epidermis. Sweat travels from the gland through the duct and out through a pore on the surface of the skin. You couldnt survive without your skin. It has many important functions. In several ways, it helps maintain homeostasis. The main function of the skin is controlling what enters and leaves the body. It prevents the loss of too much water from the body. It also prevents bacteria and other microorganisms from entering the body. Melanin in the epidermis absorbs ultraviolet light. This prevents the light from reaching and damaging the dermis. The skin helps maintain a constant body temperature. It 
 Question: __oily substance secreted by glands in the skin

Ex Output:
sebum


Ex Input:
Context: Earth is surrounded by a magnetic field (Figure 1.1) that behaves as if the planet had a gigantic bar magnet inside of it. Earths magnetic field also has a north and south pole. The magnetic field arises from the convection of molten iron and nickel metals in Earths liquid outer core. Many times during Earth history, even relatively recent Earth history, the planets magnetic field has flipped. That is, the north pole becomes the south pole and the south pole becomes the north pole. Scientists are not sure why this happens. One hypothesis is that the convection that drives the magnetic field becomes chaotic and then reverses itself. Another hypothesis is that an external event, such as an asteroid impact, disrupts motions in the core and causes the reversal. The first hypothesis is supported by computer models, but the second does not seem to be supported by much data. There is little correlation between impact events and magnetic reversals. Click image to the left or use the URL below. URL: Earths magnetic field is like a bar magnet resides in the center of the planet. 
 Question: earths magnetic field

Ex Output:

has a north and south pole.