Question

When they heard a gunfire across the border, the
relief workers in the camp knew that another
group of refugees ............... before long.​

Answer 1

By filling in space we will get ''When they heard gunfire across the border, the relief workers in the camp knew that another group of refugees had left before long.​

Explanation:

• Correcting the sentences requires the proper use of grammar.

• Proper use of grammatical organization and all the dependent and independent clauses.

• The main thing is we should focus on the use of the proper form of the verb.

• The use of 's' or 'es' depends upon the use of the form of a singular or plural verb.

Learn more about it.

20 English phrases with sentences

brainly.in/question/9925348

Answer 2

Had left is the answer

hope this would helpful