The answer to this question relies on a clear understanding of the concept of 'pronouns' in parajumbles. The sentence mentions, 'this has meant a lot of uncertainty.... around... return to office...' It indicates that the preceding sentence discusses something related to the return to the office, and that particular element has caused a significant amount of uncertainty. Just before blank 2, there is a similar idea being presented: "The flow of workers back into offices has been more of a trickle than a steady stream, and this has meant a lot of uncertainty around what a wide-scale return to the office might look like in practice..."
Anil could not go to his friend's party, as he had fever and was .
The students' picnic plans when it started raining heavily in the morning.
In his address to the candidates contesting the student council elections, the Principal said, “If you want others to take you seriously then you must ……………. on issues like gender bias and inclusivity.”
The outbreak of COVID-19 resulted in a health crisis and a drop in economic activity that were without ……….. in history. While containing and ………. the spread of the virus was the first priority of public authorities, reducing the …………… of the disease and limiting the pressure on healthcare systems were also considered equally important.