If in a developed nation the width of the bars for an age group of 35 to 40 years decreases for three successive censuses, which one of the following statements is likely to be true?
A) There has been high emigration in that age group.
B) The fertility has increased in that age group.
C) The fertility has decreased in that age group.
D) Other age groups have increased their fertility to compensate for the 35 to 40 age group.
Question 2
Good health in the modern world, with few cases of bacterial infection, is largely the result of
A) the development and widespread use of new immunizations.
B) clean water supplies and proper treatment of sewage.
C) widespread use of bleach, antibiotics, and antibacterial soaps.
D) frequent bathing and washing of clothing and dishes.
Crop plants developed by selective breeding of the wild mustard plant.
(a) Longevity decreases with increased horn-length breeding value of harvested rams. (b) Mean-weight
Part of the Hubble Ultra-Deep Field image showing a typical section of space containing galaxies int
Measurements of solar cycle variation during the last 30 years
Shifts between Warm and Cold Periods during the Last 3 Million Years
What rate, compounded once every 3 years, is equivalent to 9% effective rate?