The necessary conditions for optimality were derived calculus of variations.

The optimality method are introduced on slope cutting project in the paper.

将优化理论引入到削坡方案的选择上.

Results of performance evaluation showed that this lubricant possesses extreme-pressure, anti-rust , antifoam and fire resistant properties.

润滑剂由实验室性能评定的结果.表明该润滑剂具有极压性 、 防锈 性 、 抗泡性和难燃性.

Under certain circumstances, antifoam additives can be abnormally depleted.

在某些情况下, 抗泡沫添加剂会无缘无故的损失.

The selection panel for the national squad ought to promptly integrate new promising players.

国家队的选拔小组应当迅速引入有潜力的新队员。

By the time he turned 32, Rees had already made 23 appearances for England's national team.

在他32岁之前，里斯已经为英格兰国家队出场23次。

Clad in the national team's colors, he scarcely demonstrated his complete capabilities.

尽管身着国家队队服，他几乎没能展示出全部才能。

They have bred a new variety of rose with large flowers.

他们栽培了可开大花朵的新品种玫瑰花.

This year we will produce a new line in toothpaste.

今年我们要生产几款牙膏的新品种.

The individuals of the new variety would chiefly cross together.

这个新品种的个体通常会彼此配合.

Often during the rainy season and flood low-temperature phenomena that affect crop growth and harvest.

雨季常有低温现象和洪涝灾害,影响农作物的生长和收割.

Two-thirds of China's land are threatened by floods.

三分之二 以上的国土面积受到洪涝灾害威胁.

Catastrophic floods struck in 1998 and 1999.

1998、1999年连续遭受特大洪涝灾害.

Major floods caused damage the environment are the inevitable result.

重大的洪涝灾害都是破坏环境造成的必然结果.

Disastrous weather have drought, floods, frost, hail and strong winds.

灾害性天气有干旱 、 洪涝 、 霜冻 、 冰雹和大风.

Drought, floods, hail, wind, frost, and other meteorological disasters.

旱灾 、 洪涝 、 雹灾 、 风灾 、 霜冻等气象灾害频繁.

Even the well-designed gutter on the high road was at risk of flooding during the heavy rain.

大路上设计精良的排水沟，即使在大雨期间也有洪涝风险。

Key words: North Europe, Cruise, sightseeing on the sea.

关键词: 北欧邮轮海上观光商业.

Which ports will the ship stop at on the way?

请问邮轮沿途会停靠哪些港口?

You are marketing director for a cruise line operating truly luxurious ships.

您是营销总监的邮轮经营真正豪华的船.

Plus, we can a cruise to some of the other islands.

另外, 我们还可以搭邮轮去别的岛玩.