The answer is A. <span>effective length of the tube
In wind instrument, the effective length is not the actual length of the instrument but only the length that the finger holes manage to cover.
The more holes it managed to cover, the higher frequency of vibration it might able to produce, which lead to higher pitch of the instrument.</span>
I hope this helps you!! :)
1. water temperature of lakes and rivers rise - nuclear power plant. Water is used as a coolant to maintain the temperature of nuclear reactors. and the resulting water is warmed up.
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2.carbon monoxide pollutes air - </span> internal combustion engine. Internal combustion engines release fumes of carbon monoxide.
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3. fly ash of soot in air - </span>coal-burning power plant. Coal burning plants release ash produced in small dark flecks.<span>
4. soil contamination of water resources - </span>DDT spraying in agriculture. DDT washes off agricultural land into water resources.
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5. sewage contamination of water resources -</span>population density. Urban areas produce a low of sewage, which is usually treated before being disposed of in rivers or the sea.
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6. excess plant growth in the lakes or rivers - </span>phosphate detergents. In many rivers, algal growth is limited by phosphate. Once excess phosphate is released to rivers, exponential algal growth can occur.<span>
7.reduces farmland and plant life to cleanse air - </span>urban sprawl. Urban sprawl uses up land for houses in an inefficient manner that could have been used for farming or natural areas.
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8. studies air,water, and land - </span>ecologist. Ecology is the study of <span>relations of organisms to one another and to their physical surroundings.</span><span>
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I think the answer is false!
