When doing medical research with human subjects, which four limitations are unavoidable?

The movement of tectonic plates in two different locations is shown below: two blocks labeled location a and location b are shown. at location a the top layer of the block shows two horizontal arrows pointing towards each other. small dunes are shown in the middle between the two arrows. the block labeled b has a vertical line in the middle. on the left of the line there is an arrow pointing down. on the right of the vertical line there is an arrow pointing up which statement is most likely true? subduction may occur in both locations. earthquakes may occur in both locations. subduction may occur in location a only and a volcanic eruption may occur in location b only. an earthquake may occur in location a only and a volcanic eruption may occur in location b only.

The kind of fertilization found in the majority of aquatic animals is (internal or external) fertilization.

Quick asap will give brainiest ! what best describes the same pattern of tides on earth throughout the day? neap tides spring tides semidiurnal tides nocturnal tides