Diagnostic Test

In Raisin in the Sun, Lorraine Hansberry does not

reject integration or the economic and moral promise

of the American dream; rather, she remains loyal to

this dream while looking, realistically, at its

incomplete realization. Once we recognize this dual                        (line 5)

vision, we can accept the play’s ironic nuances as

deliberate social commentaries by Hansberry rather

than as the “unintentional” irony that Bigs by

attributes to the work. Indeed, a curiously persistent

refusal to credit Hansberry with a capacity for                                  (line 10)

intentional irony has led some critics to interpret the

play’s thematic conflicts as mere confusion,

contradiction, or eclecticism. Isaacs, for example,

cannot easily reconcile Hansberry’s intense concern

for her race with her ideal of human reconciliation.                          (line 15)

But the play’s complex view of Black self-esteem and

human solidarity as compatible is no more

“contradictory” than Du Bois’ famous,

well-considered ideal of ethnic self-awareness

coexisting with human unity, or Fanon’s emphasis on                     (line 20)

an ideal internationalism that also accommodates

national identities and roles.

According to the conventional view, serfdom in

nineteenth-century Russia inhibited economic

growth. In this view Russian peasants’ status as serfs

kept them poor through burdensome taxes in cash, in

labor, and in-kind; through restrictions on mobility;                            (line 5)

and through various forms of coercion. Melton,

however, argues that serfdom was perfectly

compatible with economic growth, because many

Russian serfs were able to get around landlords’ rules

and regulations. If serfs could pay for passports, they                           (line 10)

were usually granted permission to leave the estate. If

they could pay the fine, they could establish a

separate household; and if they had the resources,

they could hire laborers to cultivate the communal

lands, while they themselves engaged in trade or                                   (line 15)    

worked as migrant laborers in cities.

Electric washing machines, first introduced in the United States in 1925, significantly reduced the amount of time spent washing a given amount of clothes, yet the average amount of time households spent washing clothes increased after 1925. This increase is partially accounted for by the fact that many urban households had previously sent their clothes to professional laundries. But the average amount of time spent washing clothes also increased for rural households with no access to professional laundries.

The nearly circular orbits of planets in our solar
system led scientists to expect that planets around
other stars would also reside in circular orbits.
However, most known extrasolar planets reside in
highly elongated, not circular, orbits. Why? The best                                                                       (line 5)
clue comes from comets in our solar system. Comets
formed in circular orbits but were gravitationally
flung into their present-day elliptical orbits when they ventured too close to
planets. Astronomers suspect
that pairs of planets also engage in this slingshot                                                                              (line 10)
activity, leaving them in disturbed, elliptical orbits. If
two planets form in close orbits, one will be scattered
inward (toward its star), the other outward. They will
likely then travel close enough to neighboring planets
to disturb their orbits also.                                                                                                                      (line 15)

Even after numerous products made with artificial sweeteners became available, sugar consumption per capita continued to rise. Now manufacturers are introducing fat-free versions of various foods that they claim have the taste and texture of the traditional high-fat versions. Even if the manufacturers’ claim is true, given that the availability of sugar-free foods did not reduce sugar consumption, it is unlikely that the availability of these fat-free foods will reduce fat consumption.

Recent studies of sediment in the North Atlantic’s                                             
deep waters reveal possible cyclical patterns in the
history of Earth’s climate. The rock fragments in
these sediments are too large to have been transported
there by ocean currents; they must have reached their                                           (line 5)
present locations by traveling in large icebergs that
floated long distances from their point of origin
before melting. Geologist Gerard Bond noticed that
some of the sediment grains were stained with iron
oxide, evidence that they originated in locales where                                              (line 10)
glaciers had overrun outcrops of red sandstone.
Bond’s detailed analysis of deep-water sediment
cores showed changes in the mix of sediment sources
over time: the proportion of these red-stained grains
fluctuated back and forth from lows of 5 percent to                                                 (line 15)
highs of about 17 percent, and these fluctuations
occurred in a nearly regular 1,500-year cycle.
Bond hypothesized that the alternating cycles
might be evidence of changes in ocean-water                                                            
circulation and therefore in Earth’s climate. He knew                                            (line 20)
that the sources of the red-stained grains were
generally closer to the North Pole than were the
places yielding a high proportion of “clean” grains.
At certain times, apparently, more icebergs from the
Arctic Ocean in the far north were traveling south                                                   (line 25)
well into the North Atlantic before melting and
shedding their sediment.
Ocean waters are constantly moving, and water
temperature is both a cause and an effect of this
movement. As water cools, it becomes denser and                                                   (line 30)
sinks to the ocean’s bottom. During some periods, the
bottom layer of the world’s oceans comes from cold,
dense water sinking in the far North Atlantic. This
causes the warm surface waters of the Gulf Stream to
be pulled northward. Bond realized that during such                                              (line 35)
periods, the influx of these warm surface waters into
northern regions could cause a large proportion of the
icebergs that bear red grains to melt before traveling
very far into the North Atlantic. But sometimes the
ocean’s dynamic changes, and waters from the Gulf                                                (line 40)
Stream do not travel northward in this way. During
these periods, surface waters in the North Atlantic
would generally be colder, permitting icebergs
bearing red-stained grains to travel farther south in                                                
the North Atlantic before melting and depositing their                                           (line 45)
sediment.
The onset of the so-called Little Ice Age
(1300-1860), which followed the Medieval Warm
Period of the eighth through tenth centuries, may
represent the most recent time that the ocean’s                                                        (line 50)
dynamic changed in this way. If ongoing
climate-history studies support Bond’s hypothesis of
1,500-year cycles, scientists may establish a major
natural rhythm in Earth’s temperatures that could
then be extrapolated into the future. Because the                                                     (line 55)
midpoint of the Medieval Warm Period was about
A.D. 850, an extension of Bond’s cycles would place
the midpoint of the next warm interval in the
twenty-fourth century.