Directions: Find the sentence/part of the sentence having an error/errors with regard to the usage of a comma.

(i) In the scientific reality Eddington said Earth is a speck of matter whirling around a mediocre star. (ii) Both of them cast adrift among billions of more important stellar objects. (iii) But in the human reality, Earth remains the centre of the universe.

Only part (i) has an error with regard to the usage of a comma. In part (i) of the sentence, commas must be placed to enclose additional thought – Eddington said. Thus, the correct form is - (i) In the scientific reality, Eddington said, Earth is a speck of matter whirling around a mediocre star. In part (ii) there is no need for a comma; and in part (iii), the comma has been placed correctly.