Controlled population growth.
Explanation:
US is a highly developed country and it has expansive infrastructure and highly mechanized agricultural equipments. So first option is not a choice. Second, access to chemical fertilizers and pesticides in a country with such advanced agriculture infrastructure is very easy. Third US is well known for using GM crops.
US does not have a controlled population growth because if not the birth rate then migration of people to US is a major concern for that country. Thus, this will be a correct choice for the given question.
Habitat loss is contributing to the permanent loss of species, the weakening of ecosystems, and is impacting the overall health of the planet.
Example:
While tree-clearing is a significant cause of habitat loss in Australia, other major contributing factors include altered bushfire frequency and the introduction of pest species that make habitats unsafe for native species or outcompete them. Meanwhile, on the Great Barrier Reef, the impacts of human-induced climate change are altering the habitats of corals, leading to large-scale coral bleaching. Over time, destruction of such habitats leads to reduced biodiversity and weakening of the Earth’s ecosystem.
<u>Sunspots</u> are temporary phenomena on the photosphere of the Sun that appear as dark spots compared to surrounding regions. They are caused by intense magnetic activity.
Answer:
this is because Steel is more difficult to magnetise and demagnetise but an iron core makes a temporary electromagnet because its lose its magnetism when the switch is open and and steel core is used to make a permanent electromagnet
