Rachel carson’s warning in silent spring was focused on
a. overgrazing by livestock
b. global warming
c. the misuse of pesticides
d. fish stock declines

c.  on the misuse of pesticides.

Explanation:

Rachel Carson was an eminent environmentalist in USA. In her book Silent Spring she focused  on the misuse of pesticides. Silent spring suggested that the planetary ecosystem was reaching the limits what it could sustain. She even got threats for lawsuit from chemical industries. She played a vital role in spreading awareness of the environmental pollution.

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.