White House. Washington, D.C. White House, formerly known as the Executive Mansion (1810â1902), the official office and residence of the president of the United States at 1600 Pennsylvania Avenue N.W. in Washington, D.C. The White House and its landscaped grounds occupy 18 acres (7.2 hectares).
Quick Answer. Ecological balance is a theory stipulating that natural conditions, including numbers of various animal and plant species, remain stable on their own through variations over time.
Nature's checks and balances. This unit introduces students to several essential understandings. They will learn that plants and animals depend on one another for survival and organisms interact within nature to create a balance. They will also learn that humans can influence and manipulate nature.