A. (1)The population of Europe as a whole, estimated roughly at 205 million by 1800, had risen to 274 million by 1850,
and to 320 million by 1870. (2)Various reasons for the rapid population growth in Europe have been suggested.
(3)Several explanations support the notion of improved health. (4)One contributing factor to this continued growth may
have been a decline in the virulence of certain fatal diseases as a result of the cyclical potency of microbes. (5)Certainly
the curbing of cholera, through the adoption of sanitary reforms, and smallpox, as Edward Jenner's technique of
vaccination gained gradual acceptance after 1796, help to explain the population trend. (6)Also, the availability of less
expensive foods of high nutritional value-most notably the potato -- and the ability to transport foodstuffs cheaply by
rail meant European populations would not suffer as much from undernourishment as in the past. (7)The population
increase was probably also the result of rising birth rates caused by earlier marriages. (8)As serfdom declined, peasants
tended to set up households at a younger age. (9)The spread of cottage industries provided an alternate income source,
allowing more rural couples to marry and set up houserfolds even without the inheritance of land.
A3. How many major details are in this passage?
a. Two
b. Three
c. Four
d. Five