New words：
energetic [ˌenərˈdʒetɪk] adj. 精力充沛的；充满活力的；积极的get tired of 厌烦；对……厌烦；对……感到厌倦
Sample Sentences：
I get tired of eating the same breakfast every day.
He is the oldest , but most energetic of my colleagues.
My little sister is always energetic—she never gets tired of playing.
New words：
fold [foʊld]
v.折叠；包；裹
n.褶皱；褶痕
Sample Sentences：
She folded the gift in colorful paper.
He folded the map up and put it in his pocket.
There is a fold on your shirt—you need to iron it.
New words：
pest [pest] n. 害虫；害兽；害鸟；讨厌的人（或物）
Sample Sentences：
Frogs eat pests which destroy crops and carry diseases.
Several key crops failed when they were attacked by pests.
We often ignore the pest problems, insect bites that are not a big deal.
New words：
heir [er] n. 继承人；后嗣；传人
Sample Sentences：
Her duty was to produce an heir to the throne.
He is his father's only heir, as he has no sisters or brothers.
New words：
cousin [ˈkʌz(ə)n] n. 表妹；表兄；堂兄；远亲；远房亲戚；同辈表亲
Sample Sentences：
We're cousins.
Your cousin is the child of your uncle or aunt.
My cousin is a member of a drama club. It seems that he enjoys acting.