当加油量异常，偏离正常脉冲当量的（）时，在累计加油5次后，编码器应停止向计控主板发送

根据派生需求定理，在其他条件相同的情况下，若()，则劳动力需求的自身工资弹性越高。

A.最终产品的需求价格弹性越大

B.其他要素对劳动力的替代越困难

C.其他生产要素的供给弹性越大

D.劳动力成本在总成本中所占的比重越小

E.工资水平越高

铣床夹具底面上的定位键应与工作台上的T形槽宽度（）

A、相比更大

B、过渡配合

C、过盈配合

D、间隙配合

阅读理解。

     Animal experts in Croatia say a bear has learned how to trick people to let him in by knocking at the

door.

     They believe the 220- kilogram brown bear probably learned the trick while nudging (轻推) a door

to get it to open.

     Experts have a guess that the nudging was mistaken by the owners for knocking and that the bear,

pleased by the result, repeated the trick.

     The Loknar family from Gerovo in western Croatia said the bear had knocked at their door three

times and they were now refusing to answer the door.

     ''We jumped out of the window as he came in through the door and went into the kitchen to take

some food for the first time." Mum Nevenka Loknar told a reporter from a local newspaper. "I opened

the door and saw him standing there and I didn't believe my eyes at first, then I ran for it as he walked in

as if it was the most normal- thing in the world."

     Bears are a common thing in the woods around here, but no one has ever heard of a bear that knocks

at the door.

     Mum Nevenka Loknar said, "The bear is so intelligent. It's incredible. We've tried to put up lots of

obstacles to stop him coming in, like a wire fence but he still gets through. I wouldn't be surprised if he

knew how to use wire cutters (钢丝剪)."

1. According to experts in Croatia, how did the bear learn the trick?

A. By knocking at the door several times.

B. By accident.

C. By learning from the owner of a family.

D. By imitation.

2. What does the underlined word "it" in paragraph 5 refer to?

A. Eating at the kitchen.

B. Knocking at the door.

C. Walking into the house.

D. Answering the door.

3. It is ________ in Gerovo that a bear knocks at the door.

A. unusual

B. a troubling problem

C. common

D. an exciting experience

4. Mum Nevenka Loknar was surprised that the bear _____.

A. didn't attack her family

B. knew how to use wire cutters

C. jumped across her wire fence three times

D. was clever at getting through the obstacles

简述数据库和数据仓库的区别。

餐巾折花推折法分为（）和（）两种。