如果（2a+2b+1）（2a+2b﹣1）=63，那么a+b的值为 _______

阅读短文，选择正确答案。

    When this story happened, they were working around a very large house. Their job was to do the cleaning. It

was not a difficult job, but sometimes it was a little dangerous, because they had to walk below where workmen

were working. Often these workmen dropped something from the top of the house many meters high to the

ground. One morning Joe was working near the house with a cigarette(香烟) behind one of his ears. Suddenly

somebody on the top shouted, "Look out!" But Joe did not "look out". He looked up. And as he did so, a long

knife missed Joe's head, but it cut off one of his ears. At once he put his hand to one side of his head and cried

out, "I've lost an ear. Help! Help!" Jeff ran up to help his friend. "Look for my ear," Joe told him. "It must be on

the ground somewhere." Jeff looked everywhere for the missing ear. At last he found an ear on the ground. He

picked it up and carried it to Joe. "Here you are," he said, "I've found it." Joe looked at it. "No, that's not my ear."

he said, "Mine had a cigarette behind it."

1. What were Joe and Jeff? [ ]

A. Soldiers.

B. Drivers.

C. Farmers.

D. Cleaners.

2. How did Joe lose his ear? [ ]

A. He cut it off by himself.

B. Jeff cut it off with a knife.

C. A falling knife cut it off.

D. A cigarette burned it up.

3. At the end of the story Jeff found _______. [ ]

A. someone else's ear

B. Joe's ear

C. a long knife

D. a cigarette

4. From the passage, we know Joe was not _______. [ ]

A. strong

B. kind

C. foolish

D. clever

5. Which is the most possible title for this passage? [ ]

A. A Lost Ear

B. A Busy Cleaner

C. A Falling Knife

D. A forgetful Man

某钢铁厂高炉炼铁的主要反应过程如下：

（1）请在方框内填入相应物质的化学式．

（2）写出步骤②的化学方程式： _________

（3）从高炉上排出的废气叫高炉废气，请推测高炉废气的主要成份为 _________ ．

1996年12月，村民甲与县肉联厂达成口头协议：自养的黄牛两头送县肉联厂宰杀，牛肉款按净肉每斤3元5角的价格结算，牛皮、牛头和牛下水归肉联厂，甲再付肉联厂宰杀费80元。在宰杀过程中，肉联厂的屠宰工人乙在其中一头牛的下水中发现牛黄，重100克，卖得价款5000元。甲知道后与乙、县肉联厂为牛黄款归属发生纠纷。现问：

甲与县肉联厂是什么法律关系

信息隐蔽是通过 (52) 实现的。

A．传递性

B．封装性

C．抽象性

D．继承性

运行中汽轮机油的控制标准是什么？