如果（x-y）：y=1：2，那么x：y=______
根据比例的基本性质，（x-y）：y=1：2，
即2x-2y=y，得x：y=3：2，
故填3：2．
He was very sad to think that he her so much pain. [ ]
A. considered
B. offered
C. caused
D. produced
盐桥有什么作用？
