Marty Murray wrote:1) Careful reading is key to getting the right answers to RC questions. This question asks what is not in the passage mentioned as a discovery.

All of the answer choices except A describe things that were described as being discovered the passage. A, on the other hand, says "Wind erosion and carbon dioxide oceans are responsible for certain geological landforms on Mars." While this is mentioned in the passage, it is not mentioned as a discovery, but only as a possibility, something that "may be responsible for these formations."

Choose A.

2) Choice E says "The claim that there was once water on Mars has only limited and indirect support
from recent discoveries." However the passage says "Mars rovers
Opportunity and Spirit, which have been exploring the
surface of Mars since 2004, have both discovered geological
evidence of past water activity."

What the passage says is not in agreement with what is said in choice E, so what choice E says cannot be inferred from the passage.

While choice B cannot be inferred from the passage with certainty, all of the choices except for choice E have at least have some basis in what is said in the passage.

A)The presence of certain geological landforms is not definitive proof that there was
once life on Mars. "Others posit that different
explanations, such as wind erosion or carbon dioxide
oceans, may be responsible for these formations."

B)It is likely that there were few significant discoveries related to the possibility of
life on Mars prior to the mid-17th century. "As early as the mid-17th century,
astronomers observed polar ice caps on Mars"

C)The absence of a substantial global magnetic field on Mars suggests that it would
be difficult to sustain life on Mars. "And in the 1990s, it was
discovered that Mars, unlike Earth, no longer possessed a
substantial global magnetic field, allowing celestial radiation
to reach the planet's surface and solar wind to eliminate
much of Mars's atmosphere over the course of several
billion years."

D)The presence of water activity on Mars is related to the possibility of life on Mars. "More recent probes have focused on whether there was once water on Mars." "geological evidence of past water activity. These findings substantially bolster claims that there was once life on Mars."

Choose E.

nathalie1107 wrote:For question 1, I agree that A is the correct answer.
However, I still wonder why C is mentioned in the passage. The passage shows that a probe reveals a Mars without rivers, oceans but water activity can be present under other form, such as ground water. The conclusion of a Mars without water activity cannot be stated directly without the assumption that "water activity includes rivers and oceans only."

Hope someone can help me make clear on this matter.