机械结构中零部件各个要素相互位臵之间，按一定顺序排列成封闭形式的互相联系的尺寸，称为尺寸链。
参考答案：对
(2013·湖南，23)You must learn to consult your feelings and your reason________you reach any decision.
A．although
B．before
C．because
D．unless
