New words：

muscle ['mʌsl] n. 肌肉
all in 累极了；疲倦极了

Sample Sentences：

I am all in. I can't move a muscle.
Lifting weights will build arm and shoulder muscles.
By the time we got to the top of the mountain, we were all in.
Some of my friends develop their arm muscles by playing tennis.

New words：

brawn [brɔ:n] n. 体力
brawny ['brɔ:ni] adj. 健壮的；肌肉发达的
muscular ['mʌskjulə]adj. 肌肉的；强壮的；肌肉发达的

Sample Sentences：

He's got more brawn than brains.
The work requires brain as well as brawn.
His brawny/muscular chest is as strong as iron.
The muscles of his arms are very brawny/muscular.

muscle ['mʌsl] n. 肌肉

New words：

suppose [sə'pəuz] v. 假设；假定；设想；(根据所知)认为，推断，料想

Sample Sentences：

I suppose he will be back by eight o'clock.
They were supposed to be here an hour ago.
Suppose he can't come, who will do the work?
I suppose you want to borrow money from me again?

New words：

brain [brein] n. 脑；脑力；智力

Sample Sentences：

In this job you need both brains and brawn.
I suppose she has more brains than any of us.
We do not fully understand how the brain is organized.

suppose [sə'pəuz] v. (根据所知)认为，推断，料想；假设；假定；设想
brawn [brɔ:n] n. 体力

New words：

criticize ['kritisaiz] v. 批评；评论；抨击；挑剔

Sample Sentences：

You have done your best; I have nothing to criticize.
Would you like to read and criticize my new novel?
People often lose confidence when they are criticized.