Q35 to Q37:
(This passage was excerpted from
material
published in 1996.)
When a large body strikes a planet
or moon, material is ejected, thereby
creating a hole in the planet and a local
Line deficit of mass. This deficit shows
up
(5) as a gravity
anomaly: the removal
of
the material that has been
ejected to
make the hole results in an area
of
slightly lower gravity than
surrounding
areas. One would therefore expect
that
(10) all of the large multi-ring impact
basins
on the surface of Earth’s Moon
would
show such negative gravity
anomalies,
since they are, essentially, large
holes
in the lunar surface. Yet data collected
(15) in 1994 by the Clementine
spacecraft
show that many of these lunar
basins
have no anomalously low gravity
and
some even have anomalously
high
gravity. Scientists speculate that
early
(20) in lunar history, when large
impactors
struck the Moon’s surface, causing
millions of cubic kilometers of crustal
debris to be ejected, denser
material
from the Moon’s mantle rose
up
(25) beneath the impactors almost
imme-
diately, compensating for the
ejected
material and thus leaving no low
gravity
anomaly in the resulting basin. Later,
however, as the Moon grew cooler
(30) and less elastic, rebound from
large
impactors would have been only
partial
and incomplete.
Thus today such
gravitational compensation probably
would not occur: the outer layer of
the Moon is too cold and
stiff.
Q36:
The passage suggests that if the scientists
mentioned in line 19 are correct in their speculations, the large multi-ring
impact basins on the Moon with the most significant negative gravity anomalies
probably
- were not formed early in the
Moon’s history
- were not formed by the massive
ejection of crustal debris
- are closely surrounded by other
impact basins with anomalously low gravity
- were created by the impact of
multiple large impactors
- were formed when the Moon was
relatively elastic
答案是A,我想问怎么推断和去非啊？有点晕！ | 
