下列各句中没有语病的一句是( ) A．北京残奥会展示了中华文化的“仁义和宽容”，

请选择一组叙述正确的句子（）。

A．白沙糖色泽洁白明亮，晶粒整齐、透明，是白糖的再洁晶产品

B．白沙糖色泽洁白明亮，晶粒整齐、均匀坚实，水分、杂质、还原糖的含量较高

C．白沙糖色泽洁白明亮，晶粒整齐、细小绵软，水分、杂质、还原糖的含量较高

D．白沙糖色泽洁白明亮，晶粒整齐、均匀坚实，水分、杂质、还原糖的含量均低

冶炼20.0t含杂质的质量分数为3.00%的生铁，需要含氧化铁质量分数为75%的赤铁矿石的质量是多少？

某企业每年需要A零件450000件，该零件每次订货成本为400元，每件年储存成本为10元。要求：

计算A零件年采购次数；

Sequential circuit is a common logic device whose output values, at a given instant, depend upon its input values and the internal state at that instant, and whose internal state depends upon the (66) preceding input values and the preceding internal state. A sequential circuit can assume a finite number of internal states and may therefore be regarded, from an abstract (67) , as a finite (68) .

Combinational circuit is another logic device whose output values, at any given instant, depend upon the input values at that instant. A combinational circuit is a (69) of a sequential circuit whose internal state is not taken (70) .

（70）处填（）。

A．calculation

B．in account

C．audit

D．attention

使用闸板防喷器手动锁紧装置应注意哪些事项？