Based on the information present in the given passage, you need to write a correct answer to the given question. A correct answer is one that correctly and completely answers the question. Do not write answers that address the question partially or incorrectly. The correct answer must be contained in the given paragraph.

Input: Consider Input: Paragraph- Sent 1: Earth processes have not changed over time.
Sent 2: The way things happen now is the same way things happened in the past.
Sent 3: Mountains grow and mountains slowly wear away.
Sent 4: The same process is at work the same as it was billions of years ago.
Sent 5: As the environment changes, living creatures adapt.
Sent 6: They change over time.
Sent 7: Some organisms may not be able to adapt.
Sent 8: They become extinct.
Sent 9: Becoming extinct means they die out completely.
Sent 10: Some geologists study the history of the Earth.
Sent 11: They want to learn about Earths past.
Sent 12: They use clues from rocks and fossils.
Sent 13: They use these clues to make sense of events.
Sent 14: The goal is to place things in the order they happened.
Sent 15: They also want to know how long it took for those events to happen.
Question: Who wants to learn about Earth's past?.

Output: Geologists.

Input: Consider Input: Paragraph- Sent 1: The day was just breaking, as I left the tower; though it was still too dark in the house to be able to see without a light, and I took one of the study candles with me on my 'round.
Sent 2: By the time I had finished the ground floor, the daylight was creeping in, wanly, through the barred windows.
Sent 3: My search had shown me nothing fresh.
Sent 4: Everything appeared to be in order, and I was on the point of extinguishing my candle, when the thought suggested itself to me to have another glance 'round the cellars.
Sent 5: I had not, if I remember rightly, been into them since my hasty search on the evening of the attack.
Sent 6: For, perhaps, the half of a minute, I hesitated.
Sent 7: I would have been very willing to forego the task--as, indeed, I am inclined to think any man well might--for of all the great, awe-inspiring rooms in this house, the cellars are the hugest and weirdest.
Sent 8: Great, gloomy caverns of places, unlit by any ray of daylight.
Sent 9: Yet, I would not shirk the work.
Sent 10: I felt that to do so would smack of sheer cowardice.
Sent 11: Besides, as I reassured myself, the cellars were really the most unlikely places in which to come across anything dangerous; considering that they can be entered, only through a heavy oaken door, the key of which, I carry always on my person.
Question: Why did he hesitate before going into the cellar?.

Output: It's huge and weird.

Input: Consider Input: Paragraph- Sent 1: When land is cleared, habitats are lost.
Sent 2: It may be cleared for agriculture.
Sent 3: It may also be used for building new homes or businesses.
Sent 4: Within the past 100 years, the amount of land used for agriculture has almost doubled.
Sent 5: Land used for grazing cattle has more than doubled.
Sent 6: Many wetlands have also been lost to agriculture.
Sent 7: The U.S. has lost almost all the natural tall-grass prairies.
Sent 8: Thee areas of tall thick grass have virtually disappeared.
Sent 9: These areas of land had thick fertile soil.
Sent 10: Their grasses had very deep root systems.
Sent 11: These deep and thick roots reduced the amount of soil erosion.
Sent 12: They also were home to many plants and animals.
Sent 13: Prairies were wonderful places.
Sent 14: They were home to colorful flowers, prairie dogs, and herds of bison.
Question: Within the last 100 years, what has land clearing done for agriculture and cattle?.
Output: The amount of land used for both has almost doubled in size.