question 8 is based on the following graph
8.which of the following， if true， most helps explain
the difference in the rates of decline between 1980
and 1990 in population of puffins and arctic terns，
two kinds of seabirds for which sand eels serve as a
primary source of food？
（a） puffins switched in part from their preferred food
of sand eels to rockfish and other fish， but arctic
terns did not.
（b） the marked decline in the populations of puffins
and arctic terns that occurred on alair island
did not occur on other similar islands nearby，
where there are substantial populations of both
species.
（c） the decline in sand eels was due to changes in
environmental conditions that affected the
reproduction of eels rather than to overfishing
by people.
（d）the main diet of puffin and arctic tern chicks on
alair island in 1980 consisted of young sand
eels.
（e） unusual severe weather that disrupted the breed-
ing cycle of the sand eels of alair island in
1989 also damaged the nests of puffins but not
those of arctic terns.
9. peter： more than ever before in risland， college graduates with
science degrees are accepting permanent jobs in other
fields. that just goes to show that scientists in risland are
not being paid enough.
lila： no， it does not. these graduates are not working in science
for the simple reason that there are not enough jobs in science in
risland to employ all of these graduates.
which of the following， if true in risland， would most undermine
the reasoning in peter's argument？
（a） the college graduates with science degrees who are not work-
ing in science are currently earning lower salaries than they
would earn as scientists.
（b） fewer college students than ever before are receiving degrees
in science.
（c） the number of jobs in science has steadily risen in the last
decade.
（d） a significant number of college graduates with science degrees
worked at low-paying jobs while they were in college.
（e） every year some recent college graduates with science degrees
accept permanent jobs in nonscientific fields.
questions 10-15
exactly six lectures will be given one at a time at a one-
day conference. two of the lectures-s and t-will be
given by resident speakers， the other four-w， x， y， and
z-will be given by visiting speakers. at least two but
no more than four of the lectures will be given before
lunch； the remaining lectures will be given after lunch.
the following conditions must be observed：
s will be the fourth lecture.
exactly one of the lectures by a resident will be given
before lunch.
y will be given at some time before t is given.
if w is given before lunch， y will be given after lunch.