求常、偏微分方程Lie对称的REDUCE软件包

REDUCE Software Package of Solving Lie Symmetry of Ordinary& Partial Differential Equation

几类n阶常微分方程的解法

Some Solving Processes of n-Order Ordinary Differential Equations

工作场所的年龄歧视问题常被忽视。

The problem of ageism in the workplace often goes unrecognized.

你得到这样的机会，可不是常有的事。

It is not often that you get such an opportunity.

在绘画作品中死神常以骷髅形式出现。

Death is often shown in paintings as a human skeleton.

现在的天气并不是七月份常有的。

The weather at the moment is not typical for July.

花常在蜜蜂采蜜时受粉。

Flowers are often fertilized by bees as they gather nectar.

患有这种疾病的人常被社会摈弃。

People with the disease were often treated as social outcasts.

街上常有人认出他来，他习以为常了。

He is used to being recognized in the street.

这堵墙挡着常刮的风，起到一些保护作用。

The wall gives some protection from the prevailing wind.

小孩尿床是常有的事。

It is quite common for small children to wet their beds.

凡是可能出错的事他们都常拿来开玩笑。

They often joked about all the things that could go wrong.

我们过去常在晚上散步。

We would often have a walk of an evening.