Question

by the end of 1944, during the last days of nazi germany, allied forces
were about to take over the soviet union.
had blocked germany in on three sides.
had lost most of their air support.
could no longer hold normandy.

Explanation:

By the end of 1944, the Soviet Union was part of the Allied forces, so the first option is incorrect. The Allies had significant air superiority, so the third option is wrong. The Allies had successfully established and held the Normandy beachhead, so the fourth option is incorrect. The Allied forces (from the west - after D - Day, from the south - Italy, and from the east - the Soviet Union) had Germany blocked on three sides.

Answer:

had blocked Germany in on three sides.