詞匯講解：

1.concentration 集中, 專心, 濃度
如：
The tennis players need total concentration during play.
網(wǎng)球運(yùn)動員在比賽中需要全神貫注.

Stress and tiredness often result in a lack of concentration.
緊張和疲勞常使人精神不集中。

2.fluctuate vt. 使動搖
如：
To fluctuate or waver in making choices; vacillate.
猶豫選擇時來回擺動；擺動

3.demonstrate 示范, 演示, 證明

如： She demonstrated that 2 and 2 are four.
她證明2加2等于四。

Please demonstrate how the machine works.
請示范機(jī)器的使用方法。

4.scarcely 幾乎不, 簡直沒有, 勉強(qiáng)
如：
He spoke scarcely a word of English.
他幾乎連一個英文單詞都不會說。

Scarcely had he arrived when he had to leave again.
他剛剛到達(dá)就不得不又離開。

5.distractor 分散注意力的東西

(可可英語版權(quán)所有,未經(jīng)允許請勿轉(zhuǎn)載)