2. (8 points) Zombies are coming, and Fire Dragon Grass is responsible for defense:
First-stage Fire Dragon Grass always spits red flames;
Second-stage Fire Dragon Grass spits red flames half the time and blue flames the other half;
Third-stage Fire Dragon Grass always spits blue flames.
If the attack power of the second-stage Fire Dragon Grass is twice that of the first-stage Fire Dragon Grass, then the attack power of the third-stage Fire Dragon Grass is \qquad times that of the first-stage Fire Dragon Grass.
【Answer】Solution: According to the problem, the second-stage Fire Dragon Grass spends half of its time spitting blue flames, which doubles its attack power, i.e., it increases by 1 times; if the third-stage Fire Dragon Grass spends half of its time spitting blue flames, then its attack power increases by 1 times compared to the second-stage Fire Dragon Grass, because the second-stage Fire Dragon Grass increases by 1 times compared to the first-stage Fire Dragon Grass,

so the attack power of the third-stage Fire Dragon Grass is 3 times that of the first-stage Fire Dragon Grass.
Therefore, the answer is 3.