You are given a sentence and your task is to generate another sentence that supports the given input.

Oxygen molecules pass from the air space of an alveoli into its capillary bed via simple diffusion -- oxygen concentration in the air is greater than it is in the bloodstream.
Oxygen is transferred into the bloodstream by simple diffusion.

Convergent margins involving oceanic plates form volcanoes on the continent that are parallel to the trench.
At a convergent plate boundary, when one plate is oceanic, there are large volcanoes.

A carbon atom has four electrons in its outermost valence shell.

Carbon has four valence electrons .