A portal page can have only one instance of the portlet.

一个门户网站页面只能有一个portlet实例。

youdao

By the way, only one instance at a time can own a virtual IP address.

顺便提一下，一次只有一个实例能够拥有一个虚拟ip地址。

youdao

There is generally only one instance of this process on a given machine.

通常一个机器上只有一个这样的进程。

youdao

I think of data hiding as basically saying, one can only access instance values, or, we'll call them that, instance values through defined methods.

一个人仅仅可以访问实例变量，或者，我们可以这么来说，通过定义好的方法，来访问实例的变量。

麻省理工公开课 - 计算机科学及编程导论课程节选

There is only one instance since World War II of the U.S economy increasing the employment-population ratio by five percentage points in a decade: the recovery that followed Ronald Reagan's tax cuts in 1983.

WSJ: Henry Olsen: Unemployment: What Would Reagan Do?

Since 1983, when the SEC revised its rules governing money market funds, there has been only one instance of a money market fund paying investors less than the principal they invested, according to the Investment Company Institute, a trade association for U.S. investment companies.

NPR: Lehman Fallout Hits Money Market Fund

Since a strict Supreme Court ruling in 1976, there is only one comparable instance of a court issuing a gag order on a newspaper to ensure a fair trial.

ECONOMIST: Trials and the press