压缩机的压缩比是指压缩机的（）之比。
参考答案：绝对排出压力和绝对吸入压力
_________ you have tried it on, you can't imagine how pretty the new style skirt is.[ ]
A. Because
B. Although
C. Unless
D. When
下列哪项是巨幼红细胞贫血特殊的临床表现
A．食欲减退B．震颤C．口炎D．疲乏无力E．心脏扩大
