Also, Windows 7 still requires add-on security software that has to be frequently updated.

此外，Windows 7还需要安全软件插件，必须频繁更新。

youdao

You could begin with a lighting starter kit and add on security devices later.

你应该先从照明工具包入手，然后再安装安全设备。

youdao

Zell Miller will add so-called values issues to Monday's focus on national security and Tuesday's emphasis on domestic issues.

CNN: Playing to the base

The municipalities hosting two New York City-area marathons Sunday will add police and clamp new security measures on runners and spectators following last month's bombing at the Boston Marathon.

WSJ: New York Area Races Increase Security After Boston Marathon Bombing

One of the other things that has been a steep learning curve for us - painfully so, I may add -is that we have come to have unanimity on the fact that security is a precondition not only for the political progress that we have just been talking about the last 15 or so minutes, but also for economic and social progress.

NPR: Is the Iraq Surge Strategy Working?