Answer:
3. by studying plants and animals
Explanation:
Bringing harmful plants causes harm to the other species living there.
Destroying a lot of trees takes away a lot of homes from animals.
If you're just studying them no harm is being done.
Using pesticides can cause negative effects to the plants and animals who eat them.
Answer:
Read this excerpt from Robert Stawell Ball’s Great Astronomers: Though every child may now know more of the actual truths of the celestial motions than ever Ptolemy knew, yet the fact that his work exercised such an astonishing effect on the human intellect for some sixty generations, shows that it must have been an extraordinary production. We must look into the career of this wonderful man to discover wherein lay the secret of that marvellous success which made him the unchallenged instructor of the human race for such a protracted period. Based on the context of the excerpt, what does the word protracted most clearly mean? seeming to be truthful weighing an excessive amount extending in a specific direction continuing for a long time being exceptional or talented
Answer:
A retrospective cohort study
Explanation:
A cohort study is an observational study in which individuals are classified (or selected) according to exposure status (exposed and unexposed) and followed to assess the incidence of the disease over a given period of time. Cohort studies can also be used to assess the risks and benefits of using a particular medication.
In the case of the research exposed in the question, one researcher analyzed the city's records to see who among the city's retirees had spent their careers working mostly indoors, without sun exposure; and outdoors with sun exposure. The sun is a major cause of hair cancer. Once participants were enrolled and screened, the scientist researched and examined the incidence of any form of skin cancer. This is a perfect example of a retrospective cohort study.
