下列哪一项不属于切粒机日常维护内容（）。
A、保持软连接不破损
B、保持振动塞不堵塞
C、保持导流槽内干净
D、保持压缩风压力正常
参考答案：D
什么叫风力发电机组的浆距角？
A toy store regularly sells all stock at a discount of 20 percent to 40 percent. If an additional 25 percent were deducted from the discount price during a special sale, what would be the lowest possible price of a toy costing $16 before any discount ？（）
A.$5.60
B.$7.20
C.$8.80
D.$9.60
E.$15.20
