If necessary, it should be supported by drawings.

必的话，说明书应配有插图。

If necessary, you can say which department you work in.

如有必，你可说出工作所在的部门。

If necessary to be dishonest, be dishonest.

在必的时候 他可不诚实。

I can visit home every a few months if necessary.

有必的话我可几个月回一次家。

Change the from of the word if necessary.

必时改变单词的形式。

You can shorten it if necessary.

如果有必，你可缩短。

If necessary, move the victim to a safer location.

如有必，害者转移到更安全的地方。

They could, if necessary, just quietly disregard what he decreed.

如果必的话，他们可不动声色地忽略他的命令。

A supporting network of aircraft cable can be used if necessary.

必时，可使用飞机的支承网。

And you can take a couple of days off if necessary.

如果需， 你还可休息几天。

But the astronauts can take control of the spacecraft if necessary.

但是，如果有必，宇航员可控制航天器。

If necessary, binaural aids, one for each ear, can be used.

如果有必，可使用双耳助听器，每只耳朵一个。

If necessary, is the U.S. prepared to send more troops in?

如果有必，美国是否会派遣更多部队？

50.do not forget personal documents .your spectacles and medicine if necessary.

不忘记私人文件。若必别忘了带眼镜。必备药品。

1 Remove clothing using scissors if necessary unless it is stuck to the burn.

1、除非衣服粘贴在烧伤面上，否则都脱掉（必时可用剪刀帮助）。

They will send troops to maintain peace in this region if necessary.

若有必，他们派军队维护该地区的和平。

There are plans to open football stadiums for memorial services if necessary.

如有必，计划开放足球场进行悼念活动。

Rather, listening involves hearing the speaker's words and reinterpreting them, adding information if necessary.

相反，倾听包括听讲者说话并重新解释这些信息，如果有必的话，还补充一些信息。

Such a system could, if necessary, move troops quickly from one area to another.

必的话，这样的系统可部队从一个地区迅速转移到另一个地区。

She says she'll wait for me until she's sixty, if necessary!

她说她会等我到60岁，如果有必的话！