1. ally  

n. ['ælaɪ] 同盟国，盟友

France and England were allies in the Second World War.

英国和法国在二战中是盟国。

He is a close ally of the Prime Minister.

他是首相的一位亲密盟友。

vt./vi. [ə'laɪ] (使)联合，(使)结盟；联姻

ally oneself to/with sb

He allied himself with/to the other members of the committee who supported his ideas.

他与委员会里支持他观点的其他成员联合起来。

He allied himself with a powerful family by marriage.

通过联姻，他与一个有权势的家族结为亲戚。

to ally against our common enemy

联合起来对付我们共同的敌人

alliance [ə'laɪəns] n. 联盟，联合；联姻

The two parties were still too much apart to form/make an alliance.

这两个党派分歧大得还不能形成联盟。

the working class in alliance with the peasantry

与农民结成联盟的工人阶级

2. circumstance ['sɜ:kəmstəns] n. 情形，情况；环境，境遇，(经济)境况

under no circumstances

Under no circumstances should you lend him any money.

无论如何你都不能借钱给他。

under/given the circumstances

It's the best result that could be expected under the circumstances.

在这种情况下，这可能是最好的结果了。

You should soon accommodate yourself to the new circumstance.

你应尽快适应新环境。

Force of circumstance compelled us to close the business.

环境的压力迫使我们把公司关闭了。

Grants are awarded according to your financial circumstances.

补助金根据经济状况发给。

3. veteran ['vetərən] n. 老兵；老手  adj. 老练的，资深的；老兵的

a veteran of the Second World War

二战老兵

a veteran of many sports competitions

经历过许多体育比赛的一名老将

His father is a 20-year veteran of the New York Police Department.

他父亲是纽约警署一名有20年工作经验的老警察。

veteran journalist/reporter/actor

资深记者/资深演员

4. fertile ['fɜːtaɪl] adj. 肥沃的，富饶的；能生育的；多产的；有助于…发展的，促进的

fertile soil

肥沃的土壤

Some fish are very fertile: they lay thousands of eggs.

有些鱼非常多产，它们产下数以千计的卵。

The region at the time was fertile ground for revolutionary movements.

当时该地区是革命运动的沃土。

a fertile imagination/mind/brain

丰富的想象力/有创造力的头脑

fertilizer ['fɜːtɪlaɪsə] n. 肥料

Fertilizer enriches the soil.

肥料使土壤肥沃。

5. demonstrate ['demənstreɪt] vi. 游行示威  vt. 示范，演示；表现出；论证，证明

The students were demonstrating against the war.

学生们正在举行示威游行反战。

They are demonstrating for/in favour of free higher education.

他们举行示威游行，要求实行免费高等教育。

to demonstrate the force of gravity by dropping an object

通过投掷物体来演示重力的作用

I will demonstrate how the machine works.

我来演示一下这部机器怎样运作。

The chart/table/graph above demonstrates that…

以上图表展示了…

He demonstrated his courage by his actions in battle.

他在战斗中表现出了他的勇气。

The study demonstrates the link between poverty and malnutrition.

这项研究证明了贫困与营养不良之间的联系。

This research demonstrates the need to treat cancer early.

这项研究表明，癌症需要尽早治疗。