1. How many theories does the author mention?
A. One
B. Two
C. Three
D. Four
2. The passage answers which of the following questions ?
A. What is the effect of atmospheric pressure on foliage?
B. When do dead cells harm plant growth?
C. How does water get to the tops of trees?
D. Why is root pressure weak?
3. The word 'demonstrated' in line 6 is closest in meaning to
A. ignored
B. showed
C. disguised
D. distinguished
4. What do the experiments mentioned in lines 6-8 prove?
A. Plant stems die when deprived of water.
B. Cells in plant sterns do not pump water.
C. Plants cannot move water to high altitudes.
D. Plant cells regulate pressure within stems.
5. How do botanists know that root pressure is not the only force that moves water in plants?
A. Some very tall trees have weak root pressure.
B. Root pressures decrease in winter.
C. Plants can live after their roots die.
D. Water in a plant's roots is not connected to water in its stem.
6. Which of the following statements does the passage support?
A. Water is pushed to the tops of trees.
B. Botanists have proven that living cells act as pumps.
C. Atmospheric pressure draws water to the tops of tall trees.
D. Botanists have changed their theories of how water moves in plants.
7. The word 'it' in line 13 refers to
A. top
B. tree
C. water
D. cohesion-tension theory
8. The word 'there' in line 15 refers to
A. treetops
B. roots
C. water columns
D. tubes
9. What causes the tension that draws water up a plant?
A. Humidity
B. Plant growth
C. Root pressure
D. Evaporation
10. The word 'extend' in line 19 is closest in meaning to
A. stretch
B. branch
C. increase
D. rotate
11. According to the passage, why does water travel through plants in unbroken columns?
A. Root pressure moves the water very rapidly.
B. The attraction between water molecules is strong.
C. The living cell of plants push the water molecules together.
D. Atmospheric pressure supports the columns.
12. Why does the author mention steel wire in line 24?
A. To illustrate another means of pulling water
B. To demonstrate why wood is a good building material
C. To indicate the size of a column of winter
D. To emphasize the strength of cohesive forces in water
13. Where in the passage does the author give an example of a plant with low root pressure?
A. Lines 3-5
B. Lines 6-8
C. Lines 11-12
D. Lines 13-14