Problem:OPTIONS:
- it is hard to keep long-term climate records.
- they are formed under complex climate systems.
- they influence many nations.
- there is heavy rainfall in Asia.

Read the following article and answer the question. Article: Half of the world's population is affected by Asian monsoons , but monsoons are difficult to predict. American researchers have put together a 700-year record of the rainy seasons, which is expected to provide guidance for experts making weather predictions. Every year, damp air masses,known as monsoon,produce large amounts of rainfall in India, East Asia, Northern Australia and East Africa. All this wet air is pulled in by a high pressure area over the Indian Ocean and a low pressure area to the south. According to Edward Cook , a weather expert at Columbia University in New York., the complex nature of the climate systems across Asia makes monsoons hard to predict. In addition, climate records for the area are too recent and not detailed enough to be of much use. Therefore, he and a team of researchers spent more than fifteen years traveling across Asia, looking for trees old enough to provide long-term records. They measured the rings, or circles, inside thousands of ancient trees in more than 300 places. Rainfall has a direct link to the growth and width of rings on some kinds of trees. The researchers developed a document they are calling a Monsoon Asia Drought Atlas. It shows the effect of monsoons over seven centuries, beginning in the 1300s. Professor Cook says the tree-ring records show periods of wet and dry weather. "If the monsoon basically fails or is a very weak one, the trees affected by monsoons at that location might put on a very narrow ring. But if the monsoon is very strong, the trees affected by that monsoon might put on a wide ring for that year. So, the wide and narrow ring widths of the chronology that we developed in Asia provide us with a measure of monsoon variability." With all this information, researchers say they can begin to improve computer climate models for predicting the behavior of monsoons. "There has been widespread famine and starvation and human dying in the past in large droughts. And on the other hand, if the monsoon is particularly heavy, it can cause extensive... Question: It is difficult for experts to predict Asian monsoons because _ . Answer:
****
A: they are formed under complex climate systems.

Read the following article and answer the question. Article: Why can some people sleep through noises like a honking car or flushing toilet, while others are awakened by the lightest sound? To find the answer, sleep researchers at Massachusetts General Hospital conducted an unusual study of 12 self-described deep sleepers. After tests confirmed that the healthy volunteers were solid sleepers, they took part in a three-night study in the university's sleep laboratory. The participants spent the night in a big and comfortable room. But the room also included four speakers positioned near the top of the bed. During the night, the deep sleepers were subjected to 14 different recorded sounds, like street traffic, toilets flushing, an ice machine dispensing and an airplane flying overhead. Next door, the researchers monitored their sleep patterns and brain waves. As expected, all of the participants slept ly well, but there were differences in how they responded to the noisy interruptions. Some of the sleepers didn't wake up even when a sound was blasted at 70 decibels ; others were awakened by sounds at 40 or 50 decibels. The researchers discovered that the difference in a sleeper's reaction to noise could be predicted by the level of brain activity called "sleep spindles''. A sleep spindle is a burst of high-frequency brain activity coming from deep inside the brain during sleep. The source of the spindles is the thalamus, a part of the brain that sends sensory information to the rest of the cortex . Before the study, the Massachusetts researchers theorized that the spindles are the brain's way of preventing sensory information from passing through the thalamus and waking the rest of the brain during sleep. They found that the sleepers who experienced the most sleep spindles during the night were also the soundest sleepers and were least likely to be awakened by noise. Scientists already know that most people become lighter sleepers with age, most likely because older people experience less "slow wave sleep'', which is the deepest stage of sleep. People also produce... Question: Some participants can sleep well through loud noises mainly because _ . Answer:
OPTIONS:
- their brains don't respond to outside noises
- their brains react differently to noises
- they adapt to the environment quickly
- they don't pay attention to the monitors
their brains react differently to noises

Problem: OPTIONS:
- introduce some common knowledge about fridges
- teach people how to fix their fridges
- guide people to store food properly in their fridges
- let people know how to keep their fridges clean
Q: Read the following article and answer the question. Article: You may think your bathroom is often full of bacteria and so you give it a complete cleaning once a week. But how often do you clean out and disinfect your fridge? Well, probably not often enough, according to a recent study, which found out that the fridge is the second dirtiest place in your house, just behind the bathroom. Fridge temperatures were often set too high, allowing the growth of bacteria, which included E.coil, Enterobacteria, and S. aureus, all of which will give you an easy access to food poisoning. So what can you do to ensure your fridge---and your food in it---is not a health threat? For starters, clean the fridge weekly---wipe it and repeat. Make sure your fridge is at the correct temperature for storing food, between 0 and 5 degrees centigrade. Your freezer should be below-18 degrees centigrade. You can use fridge and freezer thermeters to make sure this is the case. Some modern fridges have zones to store different types of food ,such as meat and vegetables. Make sure you don't store meat in the vegetable zone, as the temperature there might be higher. Make sure you don not leave the door open too long as the temperature in the fridge will quickly rise, creating a breeding ground for bacteria. Cover food that has not been finished, and eat it within a couple of days. Keep bottles and jars closed. Keep raw meat away from cooked meat. Both should be well covered to prevent pollution. Store raw meat at the bottom of the fridge to stop juices dripping onto other foods. Finally, use common sense, and throw away old food. Question: The purpose of this text is to _ . Answer:
Answer:
let people know how to keep their fridges clean