为什么在浇铸汽轮机轴瓦时，瓦胎要先预热到一定范围的温度？_爱下问搜题

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问题问答题简答题

为什么在浇铸汽轮机轴瓦时，瓦胎要先预热到一定范围的温度？

答案

参考答案：

是为了保片瓦脱与钨金同时冷却收缩，避免发生脱胎现象。

单项选择题

根据银行卡业务管理办法的规定，信用卡持卡人的透支发生额不能超过一定的限度。下列有关信用卡透支额的表述中，正确的是( )

A．单位卡的同一账户月透支余额不得超过发卡银行对其综合授信额度的5％

B．单位卡的同一持卡人单笔透支发生额不得超过4万元(含等值外币)

C．人卡的同一账户月透支余额不得超过6万元(含等值外币)

D．个人卡的同一持卡人单笔透支发生额不得超过2万元(含等值外币)

完形填空

"Just sign here, sir," the deliveryman said as he handed Oscar Reyna a package.
The package consisted of a long, narrow box 21 wrapped in brown paper. 22 the box, Oscar saw an umbrella inside — a very old one with a beautifully carved wooden handle. 23 he had not seen it in more than 20 years, he recognized it 24 .
Oscar was 16 when he first saw the 25 umbrella. He had gone to a concert with his grandparents. As they were leaving, h noticed an umbrella on an empty seat, impressed by its 26 , Oscar felt a strong desire to find its 27 .
Oscar 28 the manager to look in the record of advance ticket sales. Just as he thought, a name matched the seat 29 Oscar had found the umbrella. The name was Mrs. Katie O'Brien.
Oscar talked his grandparents into going by Mrs. O'Brien's 30 on their way home. He rang the bell, the door opened, and an elderly woman appeared. "May I 31 you?" she asked.
"I'd like to return it if it's yours," Oscar said, 32 the umbrella as if presenting a 33 that had long been wished for.
"Why, yes! It's mine," replied Mrs. O'Brien with a 34 smile and shining eyes. "It was given to me by my father years ago. Thank you so much for returning it. May I offer you a reward for your __35_ ?"
"No, ma'am," he said, "My grandmother says that a good deed is its own reward. "
"Well, that's 36 what my father used to say. What is your name, young man?"
Years later Oscar was staring at the finely carved handle of the umbrella as he remembered Mrs. O'Brien. It was in perfect condition, considering how 37 it was. Why had it arrived here today?
As if 38 , a note fell from the paper. It reads: Mrs. O'Brien wanted to 39 this umbrella as a present for a kind, 40. gesture long ago.

C．immediately

D．neighborhood

B．turning out

D．holding out

D．determination

A．in contrast

C．in exchange

B．significant

D．sympathetic