New words：

source [sɔ:s] n. 来源；源头；根源；原因

Sample Sentences：

What is their main source of income?
Do you know the source of Amazon River?
Tourism is a major source of income for the area.

tourism ['tuərizəm] n. 旅游业；观光业

New words：

dairy [ˈdeəri]
n.牛奶场；乳品店；乳制品
adj.牛奶的；奶制的；乳品的

Sample Sentences：

We buy milk at the dairy.
The doctor has told me to avoid dairy.
Asian diets generally have less meat and fewer dairy products.

New words：

protein ['prəuti:n] n. 蛋白质
calcium ['kælsiəm] n. 钙

Sample Sentences：

Fish was a major source of protein for the working man.
Try to balance your diet by eating more fruit and less protein.
Milk products are an excellent source of calcium and protein.
It helps your bodies use calcium, which is necessary to keep your bones strong.

source [sɔ:s] n. 来源；源头；根源；原因

New words：

physical ['fizikəl] adj. 物质的；物理的；身体的；肉体的

Sample Sentences：

He had a physical examination.
Youth is the time of physical growth.
No one knows how large the physical universe is.
These are physical changes while those are chemical changes.

New words：

outshine [aut'ʃain] v. 比…做得好；使逊色；高人一筹
outshone ['aut'ʃɔn] v. outshine的过去分词和过去式

Sample Sentences：

Simon outshone his elder brother at math.
The young girl violinist outshone all the other competitors.