问题补充：
Great changes have taken place in that school. It is no longer it was 20 years ago, it was so poorly equipped.
A. what, when
B. that, which
C. what, which
D. which, that
答案：
(答案→)A. what, when
B. that, which
C. what, which
D. which, that
解析： It is no longer it was 20 years ago中， it was 20 years ago是表语从句，且句中缺少was的表语，第一空用what； it was so poorly equipped.是定语从句，先行词是20 years ago，在句中作时间状语。所以选A。
