Merchant and passenger ships are generally required to have a life preserver for every person aboard and in many cases, a certain percentage of smaller sizes for children. According to United States requirements, life preservers must design, reversible capable of being quickly adjusted to fit the uninitiated individual, and must be so designed as to support the wearer in the water in an upright or slightly backward position.

Sufficient buoyancy(浮力) to support the wearer should be retained by the life preserver after 48 hours in the water, and it should be reliable even after long period of storage. Thus it should be made of materials resistant to sunlight, gasoline, and oils, and it should be not easily set on fire.?The position in which the life preserver will support a person who jumps or falls into the water is most important, as is its tendency to turn the wearer in the water from a face-down position to an upright or slightly backward position, with his face clear of the water, even when the wearer is exhausted or unconscious.

The method of adjustment to the body should be simple, and self-evident to uninitiated persons even in the dark under the confused conditions, which follow a disaster. Thus, the life  be reversible that it is nearly impossible to get it on wrong. Catches, straps, and ties should be kept to a minimum. In addition, the life preserver must be adjustable to the wide variety of shapes and sizes of wearers, since this greatly affects the position of floating and the self-righting qualities. A suitable life  also be comfortable to wear at all times, in and out of the water, not so heavy as to encourage to take it off on shipboard while the ship is in danger, nor so burdensome that it hinders a person in the water while trying to swim.

1. The passage is mainly about____.

A) the uses of life preservers

B) the design of life preservers

C) the materials for life preservers

D) the buoyancy of life preservers

2. According to the passage, a life  be first of all ____.

A) adjustable      B) comfortable     C) self-evident     D) self-righting

3. United States Coast Guard does NOT require the life preserver to be made ____.

A) with as few strings as possible

B) capable of being worn on both sides

C) according to each wearer's size

D) comfortable and light to wear

4. By “the uninitiated individual” (Para. 1, Line. 4) the author refers to the person ____.

A) who has not been instructed how to use a life preserver

B) who has a little experience in using a life preserver

C) who uses a life preserver without permission

D) who becomes nervous before a disaster

5. What would happen if a person were supported by the life preserver in a wrong position?

A) The waves would move him backwards.

B) The water would choke him.

C) He would immediately sink to the bottom.

D) He would be exhausted or unconscious.

答案與解析：

1. B
文章主要講述了救生衣的設計。間接題型段首主旨題。C項和D項都是對救生衣設計中設計材料的說明。A項為陷阱，指救生衣的用途，盡管開頭提到，但范圍不著邊際。故只有B是正確選項。

2. D
根據文章，救生衣首先會自動扶正。事實細節題。本文第三段主要討論救生衣落水位置，應設計的能“自動扶正”,或稍向后仰。B項是對材料的描述，范圍太窄，而A和C不合題意，因此D是正確答案。

3. C
美國海岸巡邏隊不需要救生衣根據穿戴者的尺寸生產。事實細節題。A項和B項都涉及method，其相關部分見最后一段第三句，A，B，D三項都是文章中提及的，C項與本題無關的內容，因此應該選C。

4. A
“the uninitiated individual”作者指的是不知道怎么使用救生衣的人。語義指代題。根據文章最后一段第一句，我們可推出“the uninitiated individual”就是指的那些不知道怎么使用救生衣的人。故A是正確選項。

5. D
如果一個人沒有正確使用救生衣，就會發生什么？細節辨別題。第三段第一句后半句中a face-down position和本題中的 in a wrong position相對應。因此選項D“他可能太累了或者是已經失去知覺”是正確答案。

（責任編輯：liushengbao）

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