Also, in the query [dura ace track bb axle njs] the “bb” is probably referring to a bottom bracket while in the query [software update on bb color id] the “bb” probably means blackberry.
而且，在查询dura ace track bb axle njs时，"bb"指的应该是底架（bottom bracket），而在查询software update on bb color id时，这里的bb说的应该是黑莓手机（blackberry）。
2
When the guiding track framework is joined to 10m, you should make vertical of guiding track framework's axle and the base from the front and side.
导轨架接高到10米时，需用丝线坠从正面和侧面分别找正导轨架轴线与底座平面的垂直度。
3
Loading of trains is a complex issue. It involves many factors such as the axle weight, suspension system, traveling speed, track structure, geometric irregularity of lines and so on.