Finally I won the battle as Germany, with two roads still connected at the last turn. But I was playing so agressively that most of the USSR units had been destroyed, at the cost of that only 58% of the 6th army was still operational(The second objects need 65% operational on Emperor). Here are some thought after playing the game. 1. AI can't use their airforce well is the main reason why I can win the game. While I'm using fighters to intercept and sweep, bombers to attack their units, they sometimes use all of them to attack, leaving the sky defenseless. What's more, they just keep attacking my city, even my city fall to 0HP. If they choose attacking my units instead, it will certainly cause much trouble for units are very difficult to recover for lacking of materials. 2. Siege guns are so powerful! They can stack with an infantry providing support fire when being attacked. They can also stack with a tank, producing much damage, especially for the German tank with Blitz Promotion. They can also attack an enemy unit without being damaged. "No cost attack" is the biggest advantage for this unit. 3. It maybe better to build a solid "defensing line" instead of kill enemy units. 1upt means that an injured unit sometimes will help to our defence, while killing it will forcing us to face a healthy unit. Killing too much also doing much damage to our troops, makeing the second objects even more difficult to complete.