时差N小时 你对潜水艇了解多少?(上)

Some of the best moments in World War II movies occur when, during a battle at sea, a periscope¹ pokes³ up from the water, surveying the ocean terrain⁴.

二战题材的电影中一些可赞的片段是，海上作战的时候，一个潜望镜从水中穿出，用以测量海洋地形。

Cut to a submarine gliding⁵ through the depths. Torpedoes⁶ away, and the enemy battleship is doomed⁷. How do these amazing vessels⁸ rise and sink so quickly to specific depths?

镜头切换到潜水艇潜到水下。然后发射鱼雷，敌军战队注定会失败。这些神奇的军舰是如何实现快速上升下沉到特定的深度?

Although submarines are sophisticated machines, their ability to rise and sink is based on the elementary principle of buoyant force.

尽管潜艇是很复杂的机器，但它们上升下沉所依据的却是浮力的基本原理。

Say you fill your bathtub with water and put a rubber gym ball on the surface of the water.

将浴缸填满水然后在水面上放一个橡胶健身球。

It floats because the air-filled ball is less dense⁹ than the surrounding water.

它会在水面上漂着因为充气球的密度小于水的密度。

But poke² a hole in the ball and as water displaces the air, the overall density¹⁰ increases until the ball is heavy enough to sink to the bottom.

但在球上戳一个洞，用水代替健身球中的空气，其整体密度会变大，一直到该球重的足以落到水的底部。

1 periscope   

n. 潜望镜

参考例句：

• The captain aligned the periscope on the bearing.船长使潜望镜对准方位。
• Now,peering through the periscope he remarked in businesslike tones.现在，他一面从潜望镜里观察，一面用精干踏实的口吻说话。

2 poke   

n.刺，戳，袋；vt.拨开，刺，戳；vi.戳，刺，捅，搜索，伸出，行动散慢

参考例句：

• We never thought she would poke her nose into this.想不到她会插上一手。
• Don't poke fun at me.别拿我凑趣儿。

3 pokes   

v.伸出( poke的第三人称单数 )；戳出；拨弄；与（某人）性交

参考例句：

• He pokes his nose into everything. 他这人好管闲事。 来自《现代汉英综合大词典》
• Only the tip of an iceberg pokes up above water. 只有冰山的尖端突出于水面。 来自辞典例句

4 terrain   

n.地面，地形，地图

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• He knows the terrain of this locality like the back of his hand.他对这一带的地形了如指掌。

5 gliding   

v. 滑翔 adj. 滑动的

参考例句：

• Swans went gliding past. 天鹅滑行而过。
• The weather forecast has put a question mark against the chance of doing any gliding tomorrow. 天气预报对明天是否能举行滑翔表示怀疑。

6 torpedoes   

鱼雷( torpedo的名词复数 )； 油井爆破筒； 刺客； 掼炮

参考例句：

• We top off, take on provisions and torpedoes, and go. 我们维修完，装上给养和鱼雷就出发。
• The torpedoes hit amidship, and there followed a series of crashing explosions. 鱼雷击中了船腹，引起了一阵隆隆的爆炸声。

7 doomed   

命定的

参考例句：

• The court doomed the accused to a long term of imprisonment. 法庭判处被告长期监禁。
• A country ruled by an iron hand is doomed to suffer. 被铁腕人物统治的国家定会遭受不幸的。

8 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

9 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

10 density   

n.密集，密度，浓度

参考例句：

• The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
• The region has a very high population density.该地区的人口密度很高。