They prevent steam backflow from the header to the boiler.

For use with backflow preventer test cocks to protect from damage.

用于防回流阀测试旋塞,防止受到破坏.

Especially made for testing all reduced pressure zone backflow preventers.

专用于检测所有减压区防回流阀.

Backflow preventer manufactured from 300 Series stainless steel for corrosion resistance.

防回流阀采用耐腐蚀的300系列不锈钢制造.

From this causes two backflow agitation efficiency not high substantial clause.

由此引起二次回流搅动效率不高的重要原因.

However, backflow may now be creating other side effects.

不过, 眼下回流可能正在引发其它一些负面影响.

Martin soon latched on to the rules of backgammon.

马丁很快学会了下15子游戏棋的规则.

By 12:00. we were eating the dumplings. wrapped in peanut inside. backgammon or moral.

到了12:00. 我们一起吃饺子. 里面包着花生. 寓意步步高升.

'No; I am going to play backgammon with you, if you like,'said the Doctor.

“ 我不想出去.如果你乐意, 我还想跟你掷骰子呢, ” 医生说.

Is the classic game of backgammon cell phone. The screen is beautiful!

手机游戏介绍:非常经典的五子棋手机游戏. 画面很精美!

The more they probed into his background, the more inflamed their suspicions would become.

他们越调查他的背景，疑团就越多。

Robbie was there with his family, keeping rather in the background.

罗比和他的家人一起在那里，深居简出。

They were two of a kind, from the same sort of background.

他们俩是一类人，有相同的背景。

What had bonded them instantly and so completely was their similar background.

是相似的生活背景使他们很快变得亲密无间。

There is classical music playing in the background.

背景里有古典音乐在播放。

The background to the current troubles is provided by the dire state of the country's economy.

目前的问题是在国家经济岌岌可危的背景下出现的。

There was a scuffling noise in the background.

背景中有窸窸窣窣的脚步声。

The meeting takes place against a background of continuing political violence.

这次会议是在政治暴力连续不断的背景下召开的。

His background was in engineering.

他有工程学背景。

In the background was that eternal hum.

背景音是没完没了的嗡嗡声。

In some of the pictures the subjects are out of focus while the background is sharp.

一些照片背景很清晰，被摄主体却因失焦而显得模糊。