I am a four-sided shape. I have four right angels and my sides are not all equal to each other. What shape am I

On the map below, which of the following rivers is identified by blue? the huang he river the yangtze river the han river the naktong river

People keep spending additional units of a particular resource on a want until their marginal benefit is  decreasing withgreater thanless thannot affected by  their marginal cost.

What weather system might be occurring if the pressure gradient decreases and fish harvests in peru are weaker than normal