A.Clear-cutting has the effect of increasing the amount of coarse particulate matter that exits the ecosystem.
B.Clear-cutting has the effect of increasing the loss of super-fine particulate matter that exits the ecosystem.
C.Clear-cutting has little effect on the amount of fine particulate matter that exits the ecosystem.
D.Clear-cutting has the effect of increasing the loss of organic matter but not inorganic matter.
第1题
The results of experiment 2 show that,from 1993 to 2000, pH levels:
A.remained stable in the non-glacial lakes but increased in the glacial lakes.
B.decreased in the glacial lakes but decreased in the non-glacial lakes.
C.increased in the non-glacial lakes but decreased in the glacial lakes.
D.increased in the non-glacial lakes while remaining relatively stable in the glacial lakes.
第2题
25 plots remainedconstant. Which of the following alternative explana-tions is also consistent with the results?
A.The AGTB at all 25 plots increased.
B.The AGTB at all 25 plots decreased.
C.The AGTB at some of the plots increased and the AGTB at some of the plots decreased.
D.The AGTB at plots bounded by forest increased and the AGTB at plots bounded by clearingsremained constant.
第3题
izes of insectivoresand hummingbirds in the fragments studied?
A.Fragmentation increased the population sizes of both insectivores and hummingbirds.
B.Fragmentation decreased the population sizes of both insectivores and hummingbirds.
C.Fragmentation increased the population size of insectivores and decreased the population size ofhummingbirds.
D.Fragmentation decreased the population size of insectivores and increased the population size ofhummingbirds.
第4题
The main purpose of Experiment 3 was to determine how varying the:
A.battery’s voltage affected the resistor’s resistance at a given time.
B.capacitor’s capacitance affected the time required for the voltage across the capacitor to reach a setvalue.
C.capacitor’s capacitance affected the voltage across the battery at a given time.
D.resistor’s resistance affected the time required for the voltage across the capacitor to reach a setvalue.
第5题
wavelength of0.61 μm in Study 3, those reflectances would havebeen closest to which of the following?
Large plumes ;Small plumes
A.0.2;0.5
B.0.5;0.2
C.0.5;0.9
D.0.9;0.5
第6题
rate thegreatest amount of heat with the leastamount of mate-rials. Based on the results of Experiments1, 2, and3,which of the following specifications should shechoose?
A.0.50 mol Fe powder, 0.125 mol NaCl, and 0.10mol of Mg powder
B.0.50 mol Fe powder, 0.125 mol NaCl, and 0.10mol of Mg ribbon
C.0.70 mol Fe powder, 0.125 mol NaCl, and 0.10mol of Mg powder
D.0.70 mol Fe powder, 0.125 mol NaCl, and 0.10mol of Mg ribbon
第7题
aCl addedincreased from 0mol to 0.100mol, the maximum risein temperature within 15min of the start of the reac-tion:
A.increased only.
B.increased, then stayed the same.
C.decreased only.
D.decreased, then stayed the same.
第8题
between10m and 100m in diameter and traveled at a maximumspeed of 15km/sec. It exploded at an altitude of 8km andreleased energy equivalent to 20million tons of TNT. Twoscientists discuss whether this object was a comet or anasteroid.
Scientist 1
The object was a comet, a body made of ices (such asfrozen water or methane) and dust. Most of this cometarymaterial is volatile(easily vaporized) and low in density.Friction in Earth’s atmosphere heated the comet to a tem-perature at which it exploded, high above the ground. Themajority of the ices and dust were vaporized in the explo-sion, which explains why no crater was formed at the siteand why no large, identifiable fragments of the object werefound. An asteroid would not have been completelydestroyed. Intact asteroid fragments that reached theground would have created one or more craters uponimpact and left behind recoverable pieces. Evidence showsthat the object decelerated rapidly before it exploded.Because of their low density, comets are capable of suchrapid deceleration, whereas high-density objects, such asasteroids, are not.
Scientist 2
The object was a stony asteroid. As it entered Earth’satmosphere, its high speed created a large air pressure dif-ference between the area just in front of the asteroid andthe area just behind the asteroid. The large pressure differ-ence eventually exceeded the structural strength of theasteroid. The asteroid flattened, decelerated rapidly due tothe dramatic increase in its surface area, and fragmentedbefore reaching the ground. This fragmentation would haveappeared like an explosion. Calculations show that a cometbetween 10m and 100m in diameter would explode at analtitude much higher than 8km, but a stony asteroid of thatsize would fragment at or near an altitude of 8km.Recovery of large asteroid fragments is difficult due to thearea’s boggy soil; however, small, glassy fragments wererecovered and are believed to be melted and resolidifiedpieces of the asteroid.
Which of the following phrases best describes the majorpoint of difference between the 2 scientists’ hypotheses?
A.The location of the event
B.The speed the object was traveling
C.The density of Earth’s atmosphere
D.The type of object that entered Earth’s atmosphere
第9题
k would beleasthelpful in determining that rock’s grade?
A.Chlorite
B.Muscovite
C.Staurolite
D.Plagioclase
第10题
formation in a cell.After the 1940s, it was observed that mitochondria contain their own genes. This observation contradicts evidence stated in which hypothesis?
A.The DNA Hypothesis, because if genes are made of DNA, the observation would show that DNA is present outside the nucleus.
B.The DNA Hypothesis, because if genes are made of DNA, the observation would show that DNA is present inside the nucleus.
C.The Protein Hypothesis, because if genes are made of proteins, the observation would show that proteins are present outside the nucleus.
D.The Protein Hypothesis, because if genes are made of proteins, the observation would show that proteins are present inside the nucleus.
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