题干
Great changes have taken place in that factory. It is no longer _________
it was 20 years ago,_____ it was so poorly equipped.
it was 20 years ago,_____ it was so poorly equipped.
A：what ,whe
B：that ,which
C：what ,which
D：which ,that
答案(点此获取答案解析）
A
内有
两定点
,
，
在
,
，
,在
满足
与平面
