Aflatworm obtains oxygen needed for cellular respiration through simple diffusion. a human obtains oxygen by breathing it in from the air and into the lungs. which system is the flatworm missing?

Flatworms are high-flattened organisms dependent on direct diffusion as means of oxygen intake and release of carbon. This small organisms lack "fully evolved respiratory tissues such as lungs or gills and complex circulatory system as means to transport oxygen through out the body. 
>Direct diffusion of gases through the outer membranes can be used by organisms such as flatworms as a means of respiration due to their small size and simplicity.

You should provide a picture to show where the arrow is pointing and which information that is given. but there are 3 branches of the government, legislative, executive, and judicial. legislative makes laws, executives pass laws, and judicial are the courts