20200325打卡D742万思乐学Vlearn小西妈双语工程1801期136号Damon

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• 雷电小知识
  

Why does lightning falsh ?

Lightning is the flash we see when electricity jumps from a cloud.

How does lightning happen?

We’ve zoomed into a storm cloud to see.

Drops of water and ice rub against each other and make electricity.

水滴和冰水相互摩擦并发电。

What shapes can lightning make?

Forks are the most common.Other shapes are:sheets\beads\ribbons\balls.

Does lightning ever strike buildings?

Yes,so they have special lightning rods.

The rod guides the lightning safely into the ground.

Is lightning dangerous?

Yes,it can be.you’re safe indoors though.

Why does thunder rumble?

Thunder is the noise lightning makes.

Why do you see lightning before you hear thunder?

Because light travels faster than noise,so the light reaches us first.

Why is thunder so loud?

Because lightning is so hot! The air around it heats up amazingly quickly and makes a sound like an explosion.Boom!

数雷声

How far away is the storm?

Count the seconds between the lightning and thunder to find out.

3 seconds = 1 km away

5 seconds = 1 mile away

Before the storm you’d better get home.

• Tadpoles

结合科普书再叨叨一遍，刚好里面还有孑孓，把孑孓也一起说了

When Frogs mate, the male frog tends to clasp the female underneath in an embrace called amplexus.

当青蛙交配时，雄蛙将雌蛙抱在身下，这种拥抱被称为抱合（指雌的蛙或蟾产卵于水时雄的蛙或蟾抱合排精的求偶行动）。

He literally climbs on her back, reaches his arms around her "waist", either just in front of the hind legs, just behind the front legs, or even around the head. Amplexus can last several days!

他会爬到她背上，伸出双臂搂住她的“腰”，要么就在后腿前面，要么就在前腿后面，甚至是头部周围。抱合可以持续好几天!

Usually, it occurs in the water, though some species, like the bufos on the right mate on land or even in trees!

通常，它发生在水中在陆地上，尽管有些物种，就像...甚至在树上，都有合适的伴侣!

While in some cases, complicated courting behavior occurs before mating, many species of frogs are known for attempting to mate with anything that moves which isn't small enough to eat!

而在某些情况下，复杂的求爱行为发生在交配之前，众所周知，许多种类的青蛙都试图与任何可以移动的小到不能吃的东西交配。

Spawn (egg-mass)

产卵（卵块）

While in the amplexus position, the male frog fertilizes the eggs as they get are laid. Frogs tend to lay eggs single eggs in masses, whereas toads usually lay eggs in long chains.

在抱合的时候，雄蛙会在产卵时使卵受精。青蛙通常是一窝一窝的产蛋，而蟾蜍通常是一长串的产蛋。

大家看看这是谁产的蛋?

Some frogs leave after this point, but others stick around to watch over the little ones. Some have very unusual ways of caring for their young. You'll learn about some of those later in this tour!

一些青蛙在这之后离开，但其他青蛙会留下来照看这些小家伙。有些青蛙有非常不寻常的方式来照顾他们的孩子。你将在后面的旅程里了解到更多的内容!

Egg

蛋

Frogs and Toads tend to lay many many eggs because there are many hazards between fertilization and full grown frogness! Those eggs that die tend to turn white or opaque. The lucky ones that actually manage to hatch still start out on a journey of many perils.

青蛙和蟾蜍往往会下很多很多的蛋因为在受精和发育完全的青蛙之间有很多危险! 那些死掉的蛋往往会变成白色或不透明。那些真正成功孵化的幸运儿仍然开始了一段充满危险的旅程。

Life starts right as the central yolk splits in two. It then divides into four, then eight, etc.- until it looks a bit like a raspberry inside a jello cup. Soon, the embryo starts to look more and more like a tadpole, getting longer and moving about in it's egg.

当中心的蛋黄一分为二时，生命就开始了。然后它被分成4个，然后8个，等等。直到它看起来有点像果冻杯里的覆盆子。很快，胚胎开始变得越来越像蝌蚪，变长了，在蛋里移动。

Usually, about 6-21 days (average!) after being fertilized, the egg will hatch. Most eggs are found in calm or static waters, to prevent getting too rumbled about in infancy!

通常，受精后大约6-21天(平均)，蛋会孵出来。大多数蛋都是在平静或静止的水中发现的，防止初期太吵!

Some frogs, like the Coast foam-nest tree frog, actually mate in tree branches overlooking static bonds and streams. Their egg masses form large cocoon-like foamy masses. The foam sometimes cakes dry in the sun, protecting the inside moisture. When the rain comes along, after development of 7 to 9 days, the foam drips down, dropping tiny tadpoles into the river or pond below.

有些青蛙，比如海岸泡沫巢树蛙，实际上它们是在树枝上交配的，可以俯瞰静态的纽带和溪流。它们的卵团形成巨大的茧状泡沫团。泡沫有时会在阳光下变干，保护内部水分。当雨来的时候，经过7到9天的发展，泡沫滴落下来，把小蝌蚪打落到下面的河里或池塘里。

Tadpole

蝌蚪

Shortly after hatching, the tadpole still feeds on the remaining yolk, which is actually in its gut! The tadpole at this point consists of poorly developed gills, a mouth, and a tail. It's really fragile at this point. They usually will stick themselves to floating weeds or grasses in the water using little sticky organs between its' mouth and belly area. Then, 7 to 10 days after the tadpole has hatched, it will begin to swim around and feed on algae.

孵化后不久，蝌蚪仍然以剩余的蛋黄为食，其实都在它的肚子里! 此时的蝌蚪由发育不良的鳃、嘴和尾巴组成。这一点非常脆弱。它们通常会用嘴和腹部之间的小粘性器官粘在漂浮在浮草或水草上。然后，蝌蚪孵化7到10天后，它将开始四处游动，以藻类为食。

After about 4 weeks, the gills start getting grown over by skin, until they eventually disappear. The tadpoles get teeny tiny teeth which help them grate food turning it into soupy oxygenated particles. They have long coiled guts that help them digest as much nutrients from their meadger diets as possible.

大约4周后，鳃开始被皮肤覆盖，直到它们最终消失。蝌蚪有微小的牙齿，这些牙齿帮助它们把食物磨碎，把食物变成浓稠的含氧颗粒。它们有长长的盘绕着的肠道，可以帮助它们消化尽可能多的营养。

By the fourth week, tadpoles can actually be fairly social creatures. Some even interact and school like fish!

到第4周的时候，蝌蚪实际上可以成为相当社会化的生物。有些甚至像鱼一样互动和学习!

Tadpole with legs

蝌蚪的腿

After about 6 to 9 weeks, little tiny legs start to sprout. The head becomes more distinct and the body elongates. By now the diet may grow to include larger items like dead insects and even plants.

The arms will begin to bulge where they will eventually pop out, elbow first.

大约6到9周后，细小的腿开始发芽。头部变得更加清晰，身体也拉长了。到目前为止，饮食可能会增长到包括更大的物体，如昆虫尸体，甚至植物。手臂将开始膨胀，最终会从肘部开始突出。

After about 9 weeks, the tadpole looks more like a teeny frog with a really long tail. It is now well on it's way to being almost fullgrown!

大约9周后，蝌蚪看起来更像一只有着长长的尾巴的小青蛙。现在它正在成长的过程中!

Young Frog, or Froglet

小青蛙或幼蛙

By 12 weeks, the tadpole has only a teeny tail stub and looks like a miniature version of the adult frog. Soon, it will leave the water, only to return again to laymore eggs and start the process all over again!

12周的时候，蝌蚪只有很小的尾巴，看起来就像微型版的成年青蛙。很快，它就会离开水，只为了再次回到产卵和重新开始整个过程!

Frog

青蛙

By between 12 to 16 weeks, depending on water and food supply, the frog has completed the full growth cycle. Some frogs that live in higher altitudes or in colder places might take a whole winter to go through the tadpole stage...Others may have unique development stages that vary from your "traditional" tadpole-in-the-water type life cycle: some of these are described later in this tour.

在12到16周之间，根据水和食物的供应，青蛙已经完成了完整的生长周期。一些生活在较高海拔或较冷地区的青蛙可能需要整个冬天才能经历蝌蚪阶段。其他的可能有独特的发展阶段，不同于你的“传统”蝌蚪在水中的生命周期:其中一些将在文章后面描述。

Now these frogs will start the whole process again...finding mates and creating new froggies.

现在这些青蛙将重新开始整个过程…寻找伴侣，创造新的青蛙。

What's the difference between toads and frogs?

1. Toads are a type of frog. Frogs spend most of their lives around water .Toads spend more time on dry land. Their bodies are built for where they live.
2. Toad's eyes do not bulge out from the body. A poison garland is located behind each eye.
3. Frogs have teeth in upper jaws. While toads have no teeth.
4. Frog eggs laid in clusters or groups. Toad eggs laid in long chains. But a few toads give birth to live young.
5. Frog skin is moist and smooth. Toads ' skin is dry and bumpy.
6. Frogs have long powerful jumping legs. Most frogs have webbed hind feet. Toads have shorter legs for walking.

• 拓展：青蛙和蟾蜍怎么冬眠的？
  

转自公号:忆乐时光Happy Time

Frogs 青蛙

In the case of most frogs, the right place is under water. We often think that water, in the winter time, is very cold. But as we find out with the ice cube tray in the freezer, water is liquid until it’s frozen. If the water is still liquid, then it is above freezing — but not by much!

对于大多数青蛙来说，正确的地方是在水下。我们经常认为水，在冬天的时候，是很冷的。但正如我们在冰箱里发现的冰块托盘，水在冻结之前是液态的。如果水仍然是液体，那么它就高于冰点——但不会高很多!

Many of Ontario’s frogs, like the Bull Frog, Green Frog, Mink Frog and Pickerel Frog, hibernate in the water. Many think that these frogs would burrow into the muck at the bottom of a pond or river to “keep warm” and stay hidden from predators.

安大略省的许多青蛙，像牛蛙、绿蛙、水貂蛙和梭鱼蛙，都在水里冬眠。许多人认为这些青蛙会在池塘或河流底部的淤泥中挖洞以“保暖”并躲避捕食者。

But it turns out that — in order to survive the winter under the ice — they need to stay out of the mud because…these frogs breathe through their skin!

但事实证明，为了在冰下度过冬天，它们需要远离泥地，因为……这些青蛙通过皮肤呼吸!

Very cold (4°C) water holds more oxygen than warm water, which is good news for the frogs. They can simply absorb the little bit of oxygen they need directly from the water through their permeable skins.

很冷(4°C)的水比温水含有更多的氧气，这对青蛙来说是个好消息。它们可以直接通过可渗透的皮肤从水中吸收少量的氧气。

If they were buried in the mud, the supply of oxygen would quickly get used up, so that is why they stay exposed on the bottom, or perhaps nestled among rocks, logs or roots – to get a constant supply of oxygen from moving water.

如果它们被埋在泥里，氧气供应很快就会用完，这就是为什么它们会暴露在水底，或者依偎在岩石、原木或树根之间——从流动的水中获得持续的氧气供应。

Toads 蟾蜍

Toads commonly found on trails and gardens, like the American Toad, hibernate on land. The forests and fields certainly do freeze, and even the soil freezes, so toads must find a place that escapes the frost.

通常在小路和花园里发现的蟾蜍，像美洲蟾蜍，在陆地上冬眠。森林和田野当然会结冰，甚至土壤也会结冰，所以蟾蜍必须找到一个地方躲避霜冻。

American Toads must find a place on land to hibernate. To do this, they must dig into the soil, often more than 50 cm, to get below the frost line.

美洲蟾蜍必须在陆地上找到一个地方冬眠。要做到这一点，他们必须挖进土壤，通常超过50厘米，以得到以下的霜冻线。

To do this, they dig! Toads have special, hardened knobs on their hind feet that help them dig into the soil. They must dig down, often over 50 cm into the soil, to get below the frost line, where they will spend the winter.

为了做这个，他们挖!蟾蜍的后脚上有特殊的坚硬的把手，可以帮助它们深入土壤。他们必须往下挖，通常要挖到土里50多厘米深，才能挖到霜冻线以下，他们将在那里过冬。

Only once the soil temperature warms in the spring will they know their cue to emerge again.

只有当春季土壤温度上升时，它们才知道自己能再次出来的迹象。

• Life cycle of a mosquito 
  

Egg 

The eggs are laid in a cluster on the surface of still water.

Larva 

1. The larva is called a wriggler孑孓. It can only live in water.
2. It breathes air from the water surface through a breathing tube. 
3. The wriggler moults a few times. 

Pupa 

1. The pupa lives in the water.
2. It is comma-shaped. 
3. The pupa does not feed, but it can dive below the water surface to escape danger. 
4. It undergoes metamorphosis. 

Adult

1. When the adult mosquito emerges, it spreads out its wings to dry them. 
2. A female adult mosquito lays up to a few hundred eggs at a time in the water. 
3. Adult mosquitoes have different diets from their young. Female adult mosquitoes suck blood, while male adult mosquitoes feed on plant juices. 

其他毛毛虫，蟑螂，面包虫，鸡备用

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