Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Q: In the county, the population was spread out with 23.20% under the age of 18, 7.70% from 18 to 24, 27.00% from 25 to 44, 28.00% from 45 to 64, and 14.10% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 97.00 males. For every 100 females age 18 and over, there were 96.40 males.

A: Which age group had the most people?
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Q: The blockage of transcription elongation by RNA polymerase II (pol II) at a DNA damage site on the transcribed strand triggers a transcription-coupled DNA repair (TCR), which rapidly removes DNA damage on the transcribed strand of the expressed gene and allows the resumption of transcription. To analyze the effect of UV-induced DNA damage on transcription elongation, an in vitro transcription elongation system using pol II and oligo(dC)-tailed templates containing a cyclobutane pyrimidine dimer (CPD) or 6-4 photoproduct (6-4PP) at a specific site was employed. The results showed that pol II incorporated nucleotides opposite the CPD and 6-4PP and then stalled. Pol II formed a stable ternary complex consisting of pol II, the DNA damage template, and the nascent transcript. Furthermore, atomic force microscopy imaging revealed that pol II stalled at the damaged region. These findings may provide the basis for analysis of the initiation step of TCR.

A: Which gene strand is targeted by transcription-coupled repair (TCR)?
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Q: Humidity is the amount of water vapor in the air in a particular spot. We usually use the term to mean relative humidity, the percentage of water vapor a certain volume of air is holding relative to the maximum amount it can contain. If the humidity today is 80%, it means that the air contains 80% of the total amount of water it can hold at that temperature. What will happen if the humidity increases to more than 100%? The excess water condenses and forms precipitation. Since warm air can hold more water vapor than cool air, raising or lowering temperature can change airs relative humidity (Figure 1.1). The temperature at which air becomes saturated with water is called the airs dew point. This term makes sense, because water condenses from the air as dew if the air cools down overnight and reaches 100% humidity. This diagram shows the amount of water air can hold at different temperatures. The temperatures are given in degrees Cel- sius. Water vapor is not visible unless it condenses to become a cloud. Water vapor condenses around a nucleus, such as dust, smoke, or a salt crystal. This forms a tiny liquid droplet. Billions of these water droplets together make a cloud. Clouds form when air reaches its dew point. This can happen in two ways: (1) Air temperature stays the same but humidity increases. This is common in locations that are warm and humid. (2) Humidity remains the same, but temperature decreases. When the air cools enough to reach 100% humidity, water droplets form. Air cools when it comes into contact with a cold surface or when it rises. Rising air creates clouds when it has been warmed at or near the ground level and then is pushed up over a mountain or mountain range or is thrust over a mass of cold, dense air. Click image to the left or use the URL below. URL: Clouds have a big influence on weather: by preventing solar radiation from reaching the ground. by absorbing warmth that is re-emitted from the ground. as the source of precipitation. When there are no clouds, there is less insulation. As a result, cloudless days can be extremely hot, and cloudless nights can be very cold. For this reason, cloudy days tend to have a lower range of temperatures than clear days. Clouds are classified in several ways. The most common classification used today divides clouds into four separate cloud groups, which are determined by their altitude (Figure 1.2). The four cloud types and where they are found in the atmosphere. High clouds form from ice crystals where the air is extremely cold and can hold little water vapor. Cirrus, cirrostratus, and cirrocumulus are all names of high clouds. Middle clouds, including altocumulus and altostratus clouds, may be made of water droplets, ice crystals or both, depending on the air temperatures. Thick and broad altostratus clouds are gray or blue-gray. They often cover the entire sky and usually mean a large storm, bearing a lot of precipitation, is coming. Low clouds are nearly all water droplets. Stratus, stratocumulus, and nimbostratus clouds are common low clouds. Nimbostratus clouds are thick and dark. They bring steady rain or snow. Vertical clouds, clouds with the prefix "cumulo-," grow vertically instead of horizontally and have their bases at low altitude and their tops at high or middle altitude. Clouds grow vertically when strong air currents are rising upward. Precipitating clouds are nimbus clouds. Fog (Figure 1.3) is a cloud located at or near the ground . When humid air near the ground cools below its dew point, fog is formed. Each type of fog forms in a different way. Radiation fog forms at night when skies are clear and the relative humidity is high. As the ground cools, the bottom layer of air cools below its dew point. Tule fog is an extreme form of radiation fog found in some regions. San Francisco, California, is famous for its summertime advection fog. Warm, moist Pacific Ocean air blows over the cold California current and cools below its dew point. Sea breezes bring the fog

A:
clouds are classified by
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