引起皮带跑偏的因素有（）。 ["下料点不正","皮带档破","皮带接头不正","纠偏器不起作用"]
色彩纯度低的静物的特点（）。
冷害
Which one of the following characteristics is true regarding the use of hubs and switches?（） [" Hubs can have their ports be configured with VLANs"," Using hubs is costly with regard to bandwidth availability."," Switches can not forward broadcasts."," Switches are more efficient than hubs in processing frames."," Switches increase the number of collision domains in the network."]
躁狂症与躁郁症。
意象图形
