辨识国旗，选择正确的颜色单词填空。
1. Sarah's flag (旗) is ____________.
[ ]
A. red and white
B. yellow and green
2. Wu Yifan's flag (旗) is ____________.
[ ]
A. red and white
B. yellow and red
3. John's flag (旗) is ____________.
[ ]
A. red, green and white
B. blue, red and white
4. Mike's flag (旗) is ____________.
[ ]
A. blue, red and white
B. black, white and yellow