New words：

filth [filθ] n. 污秽；污物；下流言辞

Sample Sentences：

Go and wash that filth off your hand.
The floor was covered in grease and filth.
I don't want to hear that kind of filth again, you hear me?

grease [gri:s] n. 油脂

New words：

filthy ['filθi] adj.肮脏的；污秽的；下流的；卑劣的

Sample Sentences：

Take your filthy paws off me!
This place is filthy; I don't believe anyone can live here.
The rug looked filthy so I get out the vacuum and vacuum it.

New words：

groan [grəun]
v.呻吟；叹息；抱怨；发嘎吱声,受重压
n.呻吟声；叹息声；哼哼声；嘎吱声

Sample Sentences：

The dying soldier was groaning with pain.
The speaker was groaned down by the audience.
She's always groaning on about how much she has to do.

We heard the groans of the man who had fallen off the cliff.
The old chair gave a groan when the fat man sat down on it.

New words：

boomerang ['bu:mə.ræŋ] n. 回力镖

Sample Sentences：

Select a boomerang for your age and ability and then learn how to throw.
Life is like a boomerang: if you're good, good things will always come back to you.

New words：

reality [ri'æləti] n. 现实；事实；实际情况
in reality 实际上；事实上

Sample Sentences：

Will time travel ever become a reality?
It takes time for a dream to become a reality.
Everyone likes the stranger, but in reality he is a criminal.