Ants live in the hollow thorns of an acacia tree. The tree provides food and shelter for the ants. The ants protect the tree from
herbivores that might otherwise eat the tree.
Which type of relationship does this represent?
commensalism
predator/prey
mutualism
parasitism

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

How have the greenhouse gasses increased from the year 2000 to 2018

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?