Which one of the following statements concerning soil erosion is not true?
(a)-rills, and arroyos or gullies develop mainly during prolonged droughts. i am sure rates of soil erosion now exceed rates of soil formation in most parts of the world.
(b)-grasses and other vegetation, windbreaks, and contour cropping will reduce soil loss from cultivated lands.
(c)-soils form naturally by weathering; if protected from erosion, sound management can maintain or enhance their nutrient levels and textural characteristics.
(d)-i don't know yet

Salmonella typhimurium is a food-borne bacterial pathogen that can cause severe gastrointestinal disease. salmonella is often phagocytosed by macrophages that normally destroy bacterial pathogens, but this bacterium is somehow able to prevent the complete maturation of phagolysosomes. salmonella is able to tolerate the low ph of phagolysosomes, and in fact responds to the drop in ph by secreting toxins that interfere with other cellular responses. which of the following differences would you expect to contribute to the survival of a bacterium within an salmonella-containing phagosome, compared to a healthy phagolysosome? decreased activity of acid hydrolases increased activity of acid hydrolases decreased import of h+ ions increased import of h+ ions my guess is decreased activity of acid hydrolases but i'm not sure.

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative