单选题
1.Not only the students but also the old teacher ______ been changed.
A.was
B.were
C.has
D.have
正确答案：C
答案解析：not only…but also…是固定搭配，意思是：不但……而且……。它需要遵循就近原则，谓语动词应与the old teacher一致，所以答案是C。