39. _______ is certain, people’s living
问题:
39. _______ is certain, people’s living conditions in China have improved a lot since the 1980s.
A.It
B.As
C.what
D.Which
39. _______ is certain, people’s living conditions in China have improved a lot since the 1980s.
A.It
B.As
C.what
D.Which