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.

Example Input: Context: English is an important global language, but that doesn't mean it's easy to learn. Many experts have tried to make English easier for students to learn--but they weren't always successful. In 1930, Professor CK Ogden of Cambridge University invented Basic English. It had only 850 words (and just eighteen verbs) and Ogden said most people could learn it in just thirty hours. The problem was that people who learned Basic English could write and say simple messages, but they couldn't understand the answers in "real" English! It was also impossible to explain a word if it wasn't in the Basic English word list. For example, if you wanted a watermelon, you asked for "a large green fruit with the form of an egg, which has a sweet red inside and a good taste"! RE Zachrisson, a university professor in Sweden, decided that the biggest problem for learners of English was spelling, so he invented a language called Anglic. Anglic was similar to English, but with much simpler spelling. "Father" became "faadher", "new" became "nue' and "years" became "yeerz". Unfortunately for some students of English, Anglic never became popular. Even easier is the language which ships' captains use: it's called "Seaspeak". Seaspeak uses a few simple phrases for every possible situation. In Seaspeak, for example, you don't say, "I'm sorry what did you say?" or "I didn't understand, can you repeat that?" It's just "Say again." No more grammar! In the age of international communication through the Internet who knows? ... a new form of English might appear. A large number of the world's e-mails are in English and include examples of "NetLingo" like OIC (Oh, I see) and TTYL (Talk to you later). In another fifty years, English might not exist ... we will probably all speak fluent Internetish! 
 Question: According to Professor Zachrisson, what was the biggest problem for learners of English?
Example Output: spelling.

Example Input: Context: Hoping to break their current losing streak the Cardinals flew to Arrowhead Stadium for an interconference duel with the Chiefs. The Cardinals scored with kicker Jay Feely hitting a 36-yard field goal, but they fell behind with QB Matt Cassel completing a 1-yard TD pass to WR Dwayne Bowe. This was followed by RB Thomas Jones getting a 1 and a 3-yard TD run. The Cardinals responded with Feely making a 29-yard field goal, but they struggled further with kicker Ryan Succop getting a 23-yard field goal, followed by Cassel throwing a 38-yard TD pass to Bowe. The Cardinals cut the lead with QB Derek Anderson completing a 3-yard TD pass to WR Larry Fitzgerald. 
 Question: What team scored the first touchdown of the game?
Example Output: chiefs

Example Input: Context: Organisms that live in lakes, ponds, streams, springs or wetlands are part of freshwater ecosystems. These ecosys- tems vary by temperature, pressure (in lakes), the amount of light that penetrates and the type of vegetation that lives there. Limnology is the study of bodies of fresh water and the organisms that live there. A lake has zones just like the ocean. The ecosystem of a lake is divided into three distinct zones (Figure 1.1): 1. The surface (littoral) zone is the sloped area closest to the edge of the water. 2. The open-water zone (also called the photic or limnetic zone) has abundant sunlight. 3. The deep-water zone (also called the aphotic or profundal zone) has little or no sunlight. There are several life zones found within a lake: In the littoral zone, sunlight promotes plant growth, which provides food and shelter to animals such as snails, insects, and fish. In the open-water zone, other plants and fish, such as bass and trout, live. The deep-water zone does not have photosynthesis since there is no sunlight. Most deep-water organisms are scavengers, such as crabs and catfish that feed on dead organisms that fall to the bottom of the lake. Fungi and bacteria aid in the decomposition in the deep zone. Though different creatures live in the oceans, ocean waters also have these same divisions based on sunlight with similar types of creatures that live in each of the zones. The three primary zones of a lake are the littoral, open-water, and deep-water zones. Wetlands are lands that are wet for significant periods of time. They are common where water and land meet. Wetlands can be large flat areas or relatively small and steep areas. Wetlands are rich and unique ecosystems with many species that rely on both the land and the water for survival. Only specialized plants are able to grow in these conditions. Wetlands tend have a great deal of biological diversity. Wetland ecosystems can also be fragile systems that are sensitive to the amount and quality of water present within them. Click image to the left or use the URL below. URL: Marshes are shallow wetlands around lakes, streams, or the ocean where grasses and reeds are common, but trees are not (Figure 1.2). Frogs, turtles, muskrats, and many varieties of birds are at home in marshes. A salt marsh on Cape Cod in Mas- sachusetts. A swamp is a wetland with lush trees and vines found in low-lying areas beside slow-moving rivers (Figure 1.3). Like marshes, they are frequently or always inundated with water. Since the water in a swamp moves slowly, oxygen in the water is often scarce. Swamp plants and animals must be adapted for these low-oxygen conditions. Like marshes, swamps can be fresh water, salt water, or a mixture of both. As mentioned above, wetlands are home to many different species of organisms. Although they make up only 5% of the area of the United States, wetlands contain more than 30% of the plant types. Many endangered species live in wetlands, so wetlands are protected from human use. Wetlands also play a key biological role by removing pollutants from water. For example, they can trap and use fertilizer that has washed off a farmers field, and therefore they prevent that fertilizer from contaminating another body of water. Since wetlands naturally purify water, preserving wetlands also helps to maintain clean supplies of water. 
 Question: marshes are distinctive because
Example Output:
grasses and reeds are common.