Three mice are being chased by a cat. The mice were cornered when one of the mice turned around and barked, "Ruff! Ruff! Ruff!" The surprised cat ran away scared. Later when the mice told their mother what happened, she smiled and said, "You see, it pays to be bilingual!"
这里面，我指出were cornered是被动语态，其实还有一个被动语气就是 ”are being chased“，意思是（老鼠）正在被追。没有告诉大家是因为这个除了被动语态外还有一个正在进行的时态，叫进行时，意思是说当时三个老鼠正在被猫追着。它的主动语态就是一只猫正在追三只老鼠：
A cat is chasing three mice。
I am chasing a girl.
He is chasing a girl.
We are chasing a girl at the same time.
I was chasing a girl.
He was chasing a girl.
We were chasing a girl at the same time.
I will be chasing a girl.
He will be chasing a girl.
We will be chasing a girl at the same time.
被动语态： be （随人称和时态变化）+ (being + 动词ed), 这个时候，可以把被动态看成是一个固定搭配（be + chased), 在改进行时时，这个ing不是加在动词后面，而是加在be后面，being，这样就能保证动词的被动局面。
现在进行时－A girl is being chased by me 或者是 him 或者是 us
过去进行时 －A girl was being chased by me 或者是 him 或者是 us
将来进行时 － A girl will be being chased by me 或者是 him 或者是 us, 哈哈，理论上是这样，实际上基本上没有人这么用。
They’re all leaning over and looking down into the ditch. They’re all shouting and laughing. Another person is hanging from a long piece of elastic rope in the middle of the ditch. He is laughing like he is mad. The other people slowly pull him up to the bridge.
好了，今天便宜小编了，没有骂他们，至少他们没有关我的博。But I know that they are watching over my shoulder. :-)
A: Why are you crying?
B: The elephant is dead.
A: Was he your pet?
B: No, but I'm the one who must dig his grave.