移动性浊音是什么？有何临床意义？
参考答案：
因体位不同而出现的浊音区变动现象称移动性浊音，提示有腹腔积液。
I was very busy that day. Otherwise I _________in the discussion. [ ]
A. would take party
B. had taken part
C. took part
D. would have taken part
不影响曲线钢轨磨耗的因素为（）。
