Write exactly four words: begin with the two-word sequence with which, then use we as the subject and the simple past of collaborate. The research group ___ published the findings today.
الإجابة الصحيحة
with which we collaborated
الشرح
The requested formal construction places with before which, and the resulting clause identifies the research group involved in the collaboration. With that would be ungrammatical because that cannot follow a fronted preposition.