Question

Since the very first day when the umbrella company embarked upon such a dangerous research, very strange

incident ________ (take place) within the research complex​

Answer 1

Answer:

is taking place

Explanation:

Answer 2

We need to fill in the blank with the correct usage of the words given in the brackets.

• The blank can be filled with the words ' is taking place ' within the research complex.  
• From the statement, it looks as if the incident has happened in the past and is carrying on till the present.
• It looks as if a person is telling another about the incident that happened
• The words have been filled by a gerund.
• The sentence then becomes ' since the very first day when the umbrella company embarked upon such dangerous research, a very strange incident is taking place within the research complex.