| Auctions(拍卖) are public sales of goods,
conducted by an officially approved auctioneer. He asked the crowd to gather in
the auction room to bid for various items on sale. He encourages buyers to bid
higher figures and finally names the highest bidder as the buyer of the goods.
This is called “knocking down” the goods, for the bidding ends when the
auctioneer bangs a small hammer on a raised platform. The ancient Romans probably invented sales by auction and the English word comes from the Latin "autic", meaning "increase". The Romans usually sold in this way the spoils taken in war; these sales were called "sub hasta", meaning "under the spear", a spear being stuck in the ground as a signal for a crowd to gather. In England in the eighteenth and nineteenth centuries goods were often sold "by the candle"; a short candle was li A. because the auction sales took place at night B. as a signal for the crowd to gather C. to keep the auction room warm D. to limit the time when offers of prices could be made [单项选择]通过对原料存货盘点对（）进行全面检查，从而保护存货的安全。
A. 重要存货 B. 部分存货 C. 全部存货 D. 干货 [单选题] 物体静电的产生是由于两种不同物体接触或摩擦时，一种物体的( )超过界面，进入另一种物体内而产生的。
A.原子 B.电子 C.中子 D.质子 [单项选择]集中式供水的管道埋设时，应注意：饮用水管道与污水管平行时，垂直距离应有（）
A. 0.1m B. 0.4m C. 0.5m D. 1.0m E. 1.5m [填空题] 下表中列出了几种限制酶识别序列及其切割位点，图1、图2中箭头表示相关限制酶的酶切位点。请回答下列问题：
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