문제 풀다가
A : Is that Alice across the street?
B : It ____ be. She has longer hair than that.
a. can`t
b. mustn`t
이중에 b가 안되는 이유가 뭔가요?

문제 풀다가
A : Is that Alice across the street?
B : It ____ be. She has longer hair than that.
a. can`t
b. mustn`t
이중에 b가 안되는 이유가 뭔가요?
