ACT reading practice test 8

DIRECTIONS: Each passage is followed by several questions. After reading a passage, choose the best answer to each question and fill in the corresponding oval on your answer document. You may refer to the passages as often as necessary.


NATURAL SCIENCE: This passage is adapted from the article "The Pioneer Mission to Venus" by Janet G. Luhmann, James B. Pollack, and Lawrence Colin (©1994, Scientific American).

1. With regard to the possibility of returning to the planet Venus, information presented in the passage makes it clear that the author is:

A. cheerful and optimistic.
B. sarcastic and contentious.
C. doubtful and pragmatic.
D. uncertain and withdrawn.

2. Which of the following statements most accurately summarizes how the passage characterizes the state of scientific knowledge about Venus before the Pioneer mission?

F. The scientific community was hesitant to return to Venus after an earlier mission had ended in disaster.
G. Scientists saw Earth and Venus as near polar opposites in atmospheric conditions.
H. The common belief that Earth and Venus were "twins" had been eroding under the weight of scientific evidence.
J. Scientists knew little about the planet Venus because they were more interested in other planets.

3. Based on the passage, discoveries made in which two areas of study have caused scientists to re-evaluate their theories about Earth and Venus?

A. Water content and bedrock composition
B. Sulfuric gases and photosynthesis
C. Carbon dioxide and climate change
D. Atmosphere and surface temperature

4. The main point of the second paragraph (lines 17-27) is to:

F. account for the failure of the Magellan mission and to show the superiority of the Pioneer mission.
G. suggest that information from both the Magellan and Pioneer missions can bring the scientific community to a deeper understanding of Venus.
H. show that the Magellan had sent back information regarding the physical characteristics while the Pioneer had not.
J. hypothesize that the findings of the Pioneer mission will help scientists to approach problems more intelligently.

5. The passage indicates that if humans were to attempt to live on the planet Venus, survival would not be possible because:

A. of the mistaken belief that Venus and Earth are "twin" planets.
B. carbon dioxide is locked away in bicarbonate rocks, not in gaseous form.
C. the atmospheric pressure, heat, and air are not suitable for human life.
D. all of the water on Venus is condensed onto the surface.

6. According to the passage, some evidence gained before the Pioneer Venus mission suggesting that Earth and Venus are not near-twins stated that:

F. Venus produces no lead on or underneath its surface.
G. Earth was found to be much farther from the sun than was previously thought.
H. the atmosphere of Venus contains 78 percent nitrogen and 21 percent oxygen.
J. the surface temperature of Venus is 450 degrees Celsius and thus unlivable for humans.

7. As it is used in line 56, the word harbors most nearly means:

A. sails.
B. hides.
C. holds.
D. soaks.

8. According to the passage, "primordial" describes planets that:

F. are oxygen-poor due to a lack of activity by living things.
G. are not hospitable to humans because they have thick atmospheres and high surface temperatures.
H. have preserved many of the characteristics present when the planets were formed.
J. have been struck by large bodies which have altered the planets' atmospheres.

9. It can reasonably be inferred that the "activity of living things" described in line 59 directly refers to organisms on Earth that:

A. produce oxygen by their own natural processes and influence the contents of Earth's atmosphere.
B. remove sulfur gases from the atmosphere during heavy rainfall.
C. lock away carbon dioxide in carbonate rocks and maintain a reserve of the gas.
D. could easily live in oppressive atmospheres similar to the atmosphere of Venus.

10. According to the passage, the Pioneer Venus mission to Venus involved investigating details relating to the planet's:

F. surface geology and interior structure.
G. atmosphere as it has been changed by the influence of photosynthesis.
H. similarities to the planet Earth.
J. atmospheric contents.