Because the Moon and Sun are very nearly the same apparent size, totality is brief.

由于月球和太阳的表面大小非常接近，所以全食很短暂。

That's about three times the apparent size of your fist held at arms length.

这大约是你的拳头在一臂距离之外看起来的大小。

This cosmic coincidence means that the two objects just happen to be the same apparent size in our sky, which allows for one to completely block out the other.

这种宇宙的巧合意味着2个物体，从地球看上去2个一样大的物体同时出现在天空，一个恰好可以完全遮住另外一个。

Mind you, the area of sky you see here is roughly the same as the apparent size of a grain of sand held in your palm with your arm outstretched.

请注意，你在这里看到的天空面积，大致相当于你伸出手臂捧在掌心的一粒沙子的表面大小。

Um, now there’s a third way that octopus can transform themselves to blend in withor mimic their environment, and that’s by changing their shape and size, well, at least their apparent size.

嗯，现在章鱼可以通过第三种方式改变自己以融入或模仿它们的环境，那就是改变它们的形状和大小，嗯，至少是它们的外观大小。

39.Um now there's a third way that octopuses can transform themselves to blend in with or mimic their environment, and that's by changing their shape and size, at least, their apparent size.

嗯现在有第三种方式，章鱼可以改造自己融入或模仿他们的环境，这是通过改变他们的形状和大小，至少，他们的表观大小。

Um, now there's a third way that octopus can transform themselves to blend in with or mimic their environment, and that's by changing their shape and size, well, at least their apparent size.

嗯，现在章鱼可以通过第三种方式改变自己， 融入或模仿它们的环境，那就是改变它们的形状和大小， 嗯，至少是它们的表观大小。