What color is our national（国家的）flag(旗帜)? It’s ________.
The number of cars on the road is becoming _______ now in our hometown.
_______ have you been studying English? —For about 15 years. [ ]
Is this the reason __________ at the meeting for his carelessness in his work?[ ]
From March 13th, 2013, anyone under the age of 14 ______ go into Disney’s US parks alone.