通风与空调设备的隔振器安装，地面应平整，各组隔振器承受的荷载的压缩量应均匀，安装的高度误差( )。

A．应小于2mm
B．应小于5mm
C．应小于20mm
D．应小于10mm

When I was in high school, most of my friend had bicycles. I hoped I could also have it. One day I saw a second-hand bicycle, that was only one hundred yuan. I asked my father the money. But he said he could only give me half of the money. He should find the other half myself. So I went to sell newspapers after the school. My father was pleasing when I showed him the money a month after. He gives me the other fifty. You can imagine how much happy I was when I rode to school on my own bicycle.