The sentence below has two blanks, each blank indicating that something has been omitted. Choose the set of words for each blank that best fits the meaning of the sentence as a whole.

She is travelling _______ train to get to the conference.
The report was completed _______ the manager's supervision.

Option D is the correct answer.

1) "She is travelling by train":  The correct preposition to indicate the mode of transport is "by" when no article or specific detail is provided (e.g., not "the train" or "a train").
"The report was completed under the manager's supervision":

2) The preposition "under" is used to indicate the guidance or authority of someone, making it the correct choice here.

Option A: "In train" is incorrect; we use "by train" for travel.
Option B: While "by train" is correct, "with the manager's supervision" is less formal and doesn't convey authority as well as "under."
Option C: "In train" is incorrect, and "with the manager's supervision" is suboptimal.
Option E: "On train" is incorrect; we say "on the train" when referring to a specific train but "by train" for the general mode of transport.