长方形中相邻两边是互相垂直的.______.
由根据长方形的特征可知:长方形相邻的两条边互相垂直,原题说法正确,
故答案为:√.
19. I wondered_____that made him so upset.
A. how it was
B. which did it
C. what it was
D. who did it