identify the organ or structure Opening (valve) between stomach and small intestine.

Sydney drew a flow chart to illustrate the nitrogen cycle.which labels best complete the flow chart? x: producers undergo photosynthesis.y: nitrogen compounds are released into the air.x: nitrogen compounds are released into the air.y: producers undergo photosynthesis.x: free nitrogen is in the atmosphere.y: producers absorb nitrogen compounds through their roots.x: producers absorb nitrogen compounds through their roots.y: free nitrogen is in the atmosphere.

Did you know that a blue wales tongue weighs more than an elephant?

Which of the following best describes the relationship between glucose and complex molecules such as hormones?