Fill in the gap with is travelling or will travel. Dr Smith _______ to Paris tomorrow morning.

The correct answer is "is travelling". **Explanation:** We should use the present continuous tense (is travelling) when we are talking about a future arrangement. In other words, the sentence implies that Dr. Smith has already made plans and arrangements to travel to Paris tomorrow morning. Using "will travel" suggests a more spontaneous decision or a general prediction, which is less suitable in this context. So the complete sentence is: Dr Smith is travelling to Paris tomorrow morning.