Question : A) that is acidic has a low concentration of hydrogen ions B) has become increasing : 2141653
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
20) Precipitation ________.
A) that is acidic has a low concentration of hydrogen ions
B) has become increasing more basic in the last 100 years, due to industrial air pollution
C) that is acidic would have a pH lower than pure water
D) that measures pH = 4 is twice as acidic as precipitation that measures pH = 5
E) that is acidic would have a pH higher than 7
21) We use ________ to catalyze the chemical reactions of digestion.
B) nucleic acids
D) polycyclic aromatic hydrocarbons
E) alcohol molecules
22) Forming the cell walls of stems, leaves, and roots, what compound is the primary structural constituent of plant tissues?
23) Which of the following describes mass wasting?
A) blockage of sunlight by volcanic ash
B) deterioration of an atom because of radioactivity
C) downslope movement of soil and rock due to gravity
D) agricultural damage resulting from a tsunami
E) the destruction of sedimentary rock by earthquakes
24) River water held behind a dam is best described as a form of ________.
C) chemical energy
D) kinetic energy
E) potential energy
25) During photosynthesis within plants, ________.
A) oxygen and carbon dioxide are consumed
B) carbon dioxide and oxygen are produced
C) sugars and carbon dioxide are produced
D) there is net consumption of water and carbon dioxide
E) the high-quality energy from sugar is converted to heat and light
26) Cellular respiration ________.
A) releases carbon dioxide and water
B) requires the green pigment chlorophyll
C) represents a decrease in entropy
D) results in a net consumption of energy
E) involves a net consumption of water
27) Undersea earthquakes and volcanic eruptions may produce ________.
B) pyroclastic flow
E) mass wasting
28) Earthquakes result from ________.
A) global climate change
B) separation of layers within sedimentary rock
C) energy released from movement at plate boundaries and faults
D) release of gases from the underlying mantle
E) surges of magma from the earth's core
29) What is the type of rock formed when magma or lava cools?