An unstable upright equilibrium position on a vessel means that the metacenter is（）.

A . waterline B . freeboard deck C . Plimsoll mark D . amidships sectio

A . （1）作匀速曲线（非直线）运动 B . （2）作变速曲线运动 C . （3）作匀速曲线运动 D . （4）作变速直线运动

A . waterline B . freeboard deck C . plimsoll mark D . amidships sectio

A . A.具有相同的直径。 B . B.具有相同的长度。 C . C.拉伸强度相同，而剪切强度不同。 D . D.拉伸强度不同，但剪切强度相同。

A . spring-loaded line thrower B . hand thrown buoyant line C . shoulder type line throwing gun D . heaving line

A . 正确 B . 错误

A . lower than the center of gravity B . at the same height as the center of gravity C . heigher than the baseline D . on the longitudinal centerline

A . 通用螺栓 B . 头部钻孔的发动机螺栓 C . 紧公差螺栓 D . 内六方螺栓

A . sqrt（a b ），inf B . sqrt（a b ），inf C . sqrt（a b ），sqrt（a b ） D . 1，1

A . 7/139 B . 4/77 C . 1/19 D . 11/211

用AN指令改变工作号的密码时，正确的输入格式是() A.AN：123A/66 B.AN:123A/6666 C.AN:123A/666666 D.AN:123A/6A

A．47 B．72 C．76 D．123

By this time, the World War II had ended in Europe. But the Japanese refused to surrender, the Americans decided that by dropping an atomic bomb on Japan, they could end the war quickly and save more of their soldier’s lives. Soon after midnight on 6 August 1945, a bomb was dropped on the city of Hiroshima, a civilian target. No warning was given and there was total devastation. Almost all the buildings were destroyed and more than 100000 people died or were horribly wounded. The Japanese military still did not want to surrender so three days later, the Americans dropped a second atomic bomb on the city of Nagasaki, killing 45000 people. The Japanese government was discussing ending the war when they heard the news of Nagasaki. Finally, they surrendered and the World War II came to an end. At first, the scientists who had built the bomb were pleased that it had helped to end the war. However, many would come to realize that they had helped to create the most terrible weapon known to man. The first atomic bomb ______. A．was less powerful B．was dropped in Nagasaki C．was a failure D．was tested in desert

A．Y B．N C．NG

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 preserver should 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 preserver should 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 preserver should be first of all （）. A.adjustableB.comfortableC.self-evidentD.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.

A、Opportunity. B、Incentives and pressures. C、Attitudes and rationalizations.

A．They resemble candles being burnt for lovers who’ve left． B．They resemble joss sticks used in rituals for the deceaseD C．They resemble the male and female at war in families． D．They resemble knives pointed up towards heaven．