The problem of the age of empires 3 expansion.

1. The first icon of Congress is the economic blockade, which can prevent all opponents except you and your allies from sending support from the main city.

2. A spy will rise and fall. When your enemy becomes weak, he will fall and become strong, and then he will get up again.

3. When immigrants say that the population will increase by 00, they don't mean to increase the population ceiling, but that you can increase the population by 100 without building a house.