When was the last time they changed that sign?

他们多久没换标识牌了？

Its traffic infrastructure was completely revamped in just one day — that included changing 360,000 road signs.

交通设施仅仅在一天之内就彻底改造好了，其中包括 36 万个路标。

Now you can change the operation from subtraction to addition just by changing the sign after the operation.

现在，您只需更改运算后的符号即可将运算从减法更改为加法。

Some textbooks will change those signs around, so it's worth keeping track of what the positives and negatives mean.

有些书会改变这些标志，所以我应该 记住否定和肯定的语义。

Part of Oxford's approach to the language of peace is to change signs of conflict into respect for the values and hopes of the people involved.

牛津对待和平语言的方法之一，是将冲突的迹象转变为尊重相关人员的价值观和希望。

She changed position in bed deliberately, the first sign of insomnia she had ever had, and tried to think with her mother's mind about the question.

她故意改变床上的姿势， 这是她失眠的第一个迹象， 并试图用她母亲的想法来思考这个问题。