What can be inferred from Paragraph 6 about the pheromones of female snakes？
A. They are produced year round.
B. They are species specific.
C. They are only detectable by male snakes.
D. They are the strongest chemical odors.
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Which of the sentences below best expresses the essential information in the highlighted sentence in the passage？ Incorrect choices change the meaning in important ways or leave out essential information.
A. Farmers banded together and shared responsibility for protecting the manor and producing food.
B. Peasant populations had no choice but to donate their crops to their lord, for it was he who controlled the military.
C. Most manors of the time were organized similarly, consisting of a number of peasant villages surrounding the lord's estate.
D. In a manor, peasants provided labor and food in exchange for their security, which was guaranteed by a local lord.
The word These in the passage refers to
A. particles.
B. openings.
C. tips.
D. odors.
The word boosted in the passage is closest in meaning to
A. served.
B. affected.
C. raised.
D. designed.
All of the following are mentioned in Paragraph 5 and Paragraph 6 as ways in which snakes
A. avoiding animals that may pose a threat to them.
B. finding a snake of the opposite sex in order to reproduce.
C. following other snakes during cooperative hunts.
D. determining the location of potential food sources.
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