3. (8 points) During the New Year, Kangkang serves beer to guests. A bottle of beer can fill 4 glasses. When Qiuqiu pours the beer, there is always half a glass of foam in each glass, and the volume of the beer that turns into foam expands to 3 times its original volume. Therefore, when Qiuqiu pours the beer, a bottle of beer can fill ( ) glasses.
A. 5
B. 6
C. 7
D. 8
【Answer】Solution: According to the analysis, it is known that 1 portion of beer can turn into 3 portions of foam. If Qiuqiu pours beer, half of it turns into foam,

then we can divide each cup of beer Qiuqiu pours into 6 portions, so only 4 portions are left when pouring each cup. One bottle of beer can fill 4 cups, which is $4 \times 6=24$ portions. Qiuqiu pours 4 portions per cup, so the total number of cups she can pour is: $24 \div 4=6$.

Therefore, the answer is: B.