The promise of jobs and prosperity, among other factors, pulls people to cities. Half of the global population already lives in cities, and by 2050 two-thirds of the world's people are expected to live in urban areas. But in cities two of the most pressing problems facing the world today also come together: poverty and environmental degradation.
DNA is coiled into proteins,,,,which makes up ur DNA (about 6,400,000,000 basepairs (DNA building blocks) that make up your DNA) basically...and...The way DNA is packaged into chromatin is a factor in how protein production is controlled. so in your nucleus....AGAIN....DNA IS KEPT OR COILED AROUND PROTEIN YET KEPT IN UR NUCLEUS... :)
... i hope this helps somewhat..
Answer:
irritate people's breathing, ling cancer, asthma
Explanation:
Particulate matter in the air decreases life expectancy according to many researchers. Pollutants such as ozone irritate people's breathing, trigger asthma symptoms and cause lung and heart diseases. Exposure to environmental tobacco smoke causes many severe respiratory health problems such as asthma and lung cancer.
Answer:
c - having controlled experiments within ethical limits.
Explanation: