400-820-0859Fish Movement托福听力原文翻译及问题答案，今天常春藤就来为大家分析这个问题。
一、Fish Movement托福听力原文：
So we’ll continue today with the topic of fish movement and we'll focus on the role of fins.You can think of things pretty much like the arms and legs of humans.It‘s what allows movement basically.But as we will see they also do a lot more.Before we go on with the function of specific fins,I just say a few general remarks.So you get an overall picture.Fins are mainly used for moving the fish forward for propulsion as it's called,but they’re also needed for stability,steering and braking.That's right.Fish have to have a way to put on the brakes too.
Now,some fish are so fast,they‘re not good at stopping even with their fins.Requiem sharks,for example.You know,how sharks are built for speed.But these requiem sharks have difficulty stopping.They're unable to brake themselves efficiently,so they must take sharp turns in order to slow down or stop.Because of this,hmm,this brake problem.Requiem sharks avoid swimming into coral reefs.Coral reefs are usually crowded,don't allow a lot of space for large fish to take sharp turns.So these sharks roam around the outside of the coral reefs.
Um,a fish lives in a 3 dimensional world,you know,with forces pushing and pulling it in all directions.The forces in referring to are gravity,which pulls the fish downward.Buoyancy,which holds it up in the water,and something called drag.
Now,drag means to slow down,to impede movement.It's a term that applies to the effect of the force acting on any object moving through a fluid or through air.So for instance,the force of air on an airplane,drag acts to pull the airplane in the opposite direction to the direction of motion.
Well,all of these forces,gravity,buoyancy,and drag could be potentially dangerous for fish if they weren't for the fact that they have.Yep,you guessed it,fins.So,fins allow fish to keep from rolling or flipping over.They stabilize the fish's head.
Fins are crucial for determining the speed at which fish travel,to change direction.In a word,fins allow the fish to maneuver efficiently through the water.Okay.Remember,most fish have two general types of fins.
The first type is median fins.Median fins are located along the midline of the fish such as the dorsals on the back.And the caudal fins,the tail fin.The other type of fin is the paired fins at each side of the fish.
For today,the caudal fin is the one will focus on.The caudal fin,that is the tail fin.Is the main propulsive agent for most fish,it keeps them moving forward.Some fish have a broad tail that gives the fish a quick burst of speed from a standing position.And this is useful for going after a meal or swimming away from a predator.
You'll find that fast,long distance swimmers have a very long and narrow caudal fin,which is very efficient.Now,do all fish have caudal fins?No,not at all.Some sea horses and eels get along without them just fine.Well,a seahorse swims in an upright vertical position.It looks like its standing up,right.So it uses a fin on its back,the dorsal fin,as if it were a caudal fin.
And eels,well,don't really need to swim very rapidly.And like l said,most are missing the caudal fin,but most fish do have caudal fins.I give you two examples of caudal fins,and well see how they work.Okay?Let's see.I focus on the tuna and the black fish.The tuna's body is built for speed,but the caudal in,the caudal fin is key here because its moon-shaped tail creates hardly any drag in the water.And it can reach really high speeds of even 60 to 80 kilometers per hour and that's pretty amazing.
Then there's the really interesting case of the blackfish,which has a rounded caudal fin.As you can see.And in sudden bursts,it almost acts like a propeller on a plane that can even produce the sound that as an explosion.I bet you never thought of fish fin could do that.And you can see how this is useful to a fish when it goes to catch something or tries to avoid a predator.It needs to accelerate in an instant.
二、Fish Movement托福听力中文翻译：
所以今天我们将继续讨论鱼的运动，我们将重点讨论鳍的作用。你能想到的东西很像人类的胳膊和腿。它基本上允许移动。但正如我们将看到的，他们也做了很多。在我们继续讨论特定鳍的功能之前，我只说几句一般性的话。所以你得到了一个整体的画面。鳍主要用于推动鱼前进，但也用于稳定、转向和制动。这是正确的。鱼也必须有办法刹车。
有些鱼跑得很快，即使用鳍也不擅长停下来。例如，安魂曲鲨鱼。你知道，鲨鱼是如何为速度而生的。但这些安魂鲨很难阻止。他们无法有效地刹车，因此必须急转弯才能减速或停车。因为这个，嗯，刹车问题。安魂曲鲨鱼避免游进珊瑚礁。珊瑚礁通常很拥挤，不允许大鱼有很大的空间急转弯。所以这些鲨鱼在珊瑚礁外游荡。
嗯，鱼生活在三维世界里，你知道，有各种力量向各个方向推动和拉动它。这里所指的力是重力，它将鱼向下拉。浮力，在水中保持住它，还有一种叫做阻力的东西。
现在，拖动意味着减速，阻碍运动。这是一个术语，适用于任何物体在流体或空气中运动时所受的力。例如，飞机上的空气力，阻力，作用是将飞机拉向与运动方向相反的方向。
所有这些力，重力，浮力和阻力，如果不是因为它们已经存在的话，对鱼类来说都可能是危险的。没错，你猜对了，芬斯。因此，鱼鳍可以防止鱼滚动或翻身。它们稳定了鱼头。
鱼鳍对于决定鱼的移动速度和改变方向至关重要。一句话，鱼鳍可以让鱼在水中有效地移动。可以记住，大多数鱼有两种鳍。
第一种是中间鳍。中间鳍位于鱼的中线，如背部的背侧。还有尾鳍，尾鳍。另一种鳍是鱼两侧的成对鳍。
今天，我们将重点关注尾鳍。尾鳍，即尾鳍。是大多数鱼类的主要推进剂，它使它们前进。有些鱼有一条宽尾巴，这使鱼从站立的位置快速爆发。这对于饭后或游泳远离捕食者很有用。
你会发现快速、长距离游泳的人有很长很窄的尾鳍，这是非常有效的。现在，所有的鱼都有尾鳍吗？不，一点也不。有些海马和鳗鱼没有它们也过得很好。海马以直立的姿势游泳。它看起来像是站着的，对吧。所以它在背上有一个鳍，背鳍，就好像它是尾鳍一样。
鳗鱼其实不需要游得很快。正如我所说，大多数鱼都没有尾鳍，但大多数鱼都有尾鳍。我给你们举两个尾鳍的例子，看看它们是如何工作的。可以让我们看看。我关注的是金枪鱼和黑鱼。金枪鱼的身体是为了速度而造的，但尾鳍在这里是关键，因为它的月亮形状的尾巴在水中几乎不会产生任何阻力。它甚至可以达到每小时60到80公里的高速，这真是太神奇了。
还有一个非常有趣的黑鱼案例，它有一个圆形的尾鳍。如你所见。在突然爆发时，它几乎像飞机上的螺旋桨一样，甚至能发出爆炸声。我打赌你从没想过鱼翅能做到这一点。你可以看到，当鱼去抓东西或试图躲避捕食者时，这对它是多么有用。它需要在瞬间加速。
三、Fish Movement托福听力问题：
Q1:What is the main purpose of the lecture?
A.To highlight the dangers fish encounter
B.To compare the movement of fish and humans
C.To discuss the function of certain fish fins
D.To show the way in which fish fins have evolved
Q2:According to the professor,what problem do requiem sharks have when swimming?
A.Their large fins cause decreased bouyancy.
B.Their fins do not function well as brakes.
C.They cannot make sharp turns.
D.They are unable to accelerate rapidly.
Q3:How does the professor illustrate the meaning of the term“drag”?
A.By describing the movement of arms and legs
B.By mentioning the case of the propeller
C.By explaining how fish escape from predators
D.By comparing it to the force of air on an airplane
Q4:Why does the professor mention sea horses and eels?
A.To illustrate that not all fish have a caudal fin
B.To give an example of buoyancy
C.To discuss long-distance swimmers
D.To show how long,narrow tail fins function
Q5:According to the professor,what do rounded caudal fins allow the fish to do?
A.To brake more effectively
B.To keep their balance
C.To gain speed rapidly
D.To change direction
Q6:Why does the professor say this:
A.She wants the students to make predictions on the speed of fish.
B.She wants to show how fish communicate with one another.
C.She thinks the students have not read the textbook thoroughly.
D.She wants to convey the extraordinary power of some fins.
四、Fish Movement托福听力答案：
A1:正确答案：C
A2:正确答案：B
A3:正确答案：D
A4:正确答案：A
A5:正确答案：C
A6:正确答案：D
