问题 问答题 简答题

张力减径机的作用是什么?一套张力减径机一般由几架组成?

答案

参考答案:

在钢管减径过程中,张力减径机是利用轧辊的转速调整使机架间产生张力,从而不但可以减小钢管的外径,而且可以减小钢管的壁厚,与定径机和无张力减径机相比,钢管变形量最大,总减径量最大可达75~80%,减壁量可达35~40%,总延伸系数可达6以上。机架数一般大于14架。而平均张力系数小于0.5时,又称微张力减径机,此时减径量亦相对较小。

阅读理解

Julio loves to visit his grandmother . He doesn’t get to visit her very often because his family lives in a city that is six hours away .His grandmother lives in a big wooden house on a farm .It is old and looks as if it has secret hiding places .

On the third Sunday of June ,Julio’s parents took him to his grandmother’s .Since it was summer vacation, he was going to stay at grandmother’s for a whole summer . Hid cousins Mario and linda would soon be arriving. They would also be staying at their grandmother’s this summer .

A big porch (走廊) wrapped (缠绕)around two sides of the house .Julio sat in the porch swing (秋千).He could see the trees that circle the house .They had been planted as a windbreak (防风林).They protected the house from the wind and blowing dirt .The house was in the middle of a large flat field .

Julio watched the dirt road that led to the house .He couldn’t wait for his cousins to get there .Mario was his age ,and Linda was a year younger .They had fun together .Last summer they spent one whole morning making a fort out of sacks of seed (装种子的麻袋做成的堡垒).Then Uncle Henry took them on a tractor ride.

Julio remembered another time with his cousins .They had gone out to explore the fields .Julio touched an electric fence and got a shock .Then they found an old snake skin. Nothing like that ever happened at his own home !

Julio could smell the dinner that his grandmother was cooking .It made him hungry .

Finally he saw a cloud of dust coming up the road .“They’re here ! They are here !”He shouted .

根据材料内容选择最佳答案。并将其标号填入题前括号内。

小题1:Why doesn’t Julio often visit his grandmother ?

A.Because he doesn’t love his grandmother.

B.Because his parents don’t let him visit his grandmother.

C.Because his home is far away from his grandmother's.

D.Because he is often ill .小题2:Who is the youngest of Julio and his cousins ?

A.Linda.

B.Julio.

C.Mario.

D.Henry.小题3:The story tells about Julio and his cousins doing all of the following except_____.

A.watching old movie

B.taking a tractor ride

C.finding a snake skin

D.making a fort from seed sacks小题4:How do you think Julio felt when he saw his cousins arriving?

A. He was worried.

B. Ht: was excited.

C.He was angry .

D. He was sad小题5:After Julio cousins arrive , when would probably happen next ?

A.They would build a fort on the hill

B.They would look for snake skins .

C.They would climb the trees in their grandmother’s yard

D.They would eat dinner at their grandmother’s house

单项选择题