题目

 The restaurant is no longer          it was 20 years ago,         it was so poorly run.    A. what; when                          B. that; which     C. what; which         D. which; that 答案：A直线a、b、c在同一平面内，且a与b互相垂直，b与c互相垂直，那么a与c互相( )。A.垂直B.平行C.平行或垂直