问题 问答题 简答题

什么是顺牵伸和倒牵伸?各有什么特点?

答案

参考答案:

倒牵伸即头道牵伸倍数稍大与并合数,二道牵伸倍数稍小于或等于并合数。这种牵伸形式由于头道并条喂入的生条纤维紊乱,牵伸力较大,半熟条均匀度差,经过二道并条机配以较小的牵伸倍数,可以改善条干均匀度。但这种牵伸装置由于喂入头道并条机时前弯钩纤维居多,较大的牵伸倍数不利于前弯钩伸直。

顺牵伸即头道并条机牵伸倍数小于并合数,二道并条机牵伸倍数稍大于并合数,形成头道小、二道大的牵伸配置。这种配置有利于弯钩纤维的伸直,且牵伸力合理,熟条质量较好。

阅读理解

阅读理解。

     For all the dinner table, a glass of milk seems to be a constant, at least it was when I was growing up.

It was widely believed that milk was integral in building strong bones and teeth. There's no doubt that

dairy products (乳制品), and milk in particular, are high in protein and calcium, and most milk products

are supplemented with Vitamin D and A.

     While it's well known that our bones need calcium, some studies suggest that high calcium intake

doesn't necessarily lower a person's risk for fractures (骨折). A Harvard study found that people who

drank two or more glasses of milk had no greater protection from breaking a bone than those who drank

a glass or less a week.

     There's no doubt that we need calcium. Some anti-dairy supporters claim that dairy can lead to heart

disease. Much of this claim is based on high fat and high dairy products, like cheeses and creams, which

may indeed contribute to cardiovascular problems. Some studies have linked high milk intakes with a risk

of prostate cancer; this seems to be caused by high-fat dairy products, not dairy in general.

     Although milk was always regarded as one of the most important thing we need for our bones, yet

least promoted, factors involved in strengthening bones. Perhaps we should think of dairy as less like a

nutrient and more like a food. If you like it, eat it. If not, find some others. Because some claims may not

be completely true, when I eat a cream, I'm not thinking about calcium, protein, or any such thing I'm

thinking delicious.

1. Which of the following is TRUE on the milk?

A. The more milk you drink, the more risk for fractures you might be.

B. The more milk you drink, the less risk for fractures you might be.

C. The less milk you drink, the less risk for fractures you might be.

D. There is no link between them.

2. Some anti-dairy supporters claim that dairy can lead to except _________.

A. cardiovascular problems

B. heart disease

C. prostate cancer

D. stomach cancer

3. The underlined words "some others" in the last paragraph refer to _________.

A. dairy products      

B. milk

C. food

D. cream

4. What's the author's attitude towards milk?

A. He doesn't like milk any more.  

B. He used to drink milk as a child.

C. He regards milk as a nutrient.      

D. He always cares about calcium, protein when he eats something.

5. We can learn from the text that _________.

A. All the claims are not completely true.      

B. High milk intakes can lead to cancer.

C. It's necessary for you to reduce milk intakes.    

D. Give up milk for your health.

填空题