Â©2003 Why is there a decision to make about having mammograms to screen for breast cancer? A mammogram every two years to screen for breast cancer reduces the chance of dying from breast cancer among women aged 50 to 69 years. It is unclear if women aged 70 years and older get the same benefits. mammogram every two years to screen for breast cancer reduces the chance of dying from breast cancer among women aged 50 to 69 years. It is unclear if women aged 70 years and older get the same benefits.
Temperate grasslands are located north of the Tropic of Cancer (23.5 degrees North) and south of the Tropic of Capricorn (23.5 degrees South). The major temperate grasslands include the veldts of Africa, the pampas of South America, the steppes of Eurasia, and the plains of North America.
Grasslands cover about 30 percent of the Earthâs surface. The country of Africa contains the largest area of grasslands, covering about 14.5 square kilometers. There are many animals that depend on this land to live, such as African elephants, lions, zebras, giraffes, black rhinos, prairie dogs, and more.