School-master = School-mistress

Scientists hope that data from this expedition will pave the way for a more detailed exploration of Mars.

Self = Selves

Self-reliance is the best resort.

Self-reliance is the best resort.

Sense- Sensible

Shakib is the best player in the team.

Shanto played as though he had seen the ball clearly.

She broke a branch of a nearby tree and dropped it into the water. 

She cried gaily in the time of jumping into a cab.

She is a university student. 

She is blind to her son's fault. 

She is blind  to her son's fault.

She is mainly a linguistic and she is also a novelist.

She is not only a novelist but also a linguistic.