At first, the speaker was referring to the problem of pollution but halfway in her speech, she suddenly ____ to another subject.
A.remained
B.switched
C.translated
D.spent
正确答案是B
At first, the speaker was referring to the problem of pollution but halfway in her speech, she suddenly ____ to another subject.
A.remained
B.switched
C.translated
D.spent
正确答案是B