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.

New words：

ostrich ['ɔstritʃ] n. 鸵鸟；逃避现实的人

Sample Sentences：

Face the reality. Stop being an ostrich.
Ostrich is a type of large bird that can run very fast.
The short-distance runner wishes he could run as fast as the ostrich.

reality [ri'æləti] n. 现实；事实；实际情况

New words：

kangaroo [.kæŋgə'ru:] n. 袋鼠
koala [kəu'ɑ:lə] n. 树袋熊；考拉熊；无尾熊

Sample Sentences：

Australia is the hometown of kangaroos.
The mother kangaroo has a special bag for her baby.
There are over 600 animals there, including kangaroos, koalas and crocodiles.