附加锁

extra cost───额外费用；额外成本；追加费用

fit a lock───装上锁

extra boost───额外的动力

extra cover───（板球）额外堵截员

extra hours───额外时间

extra layer───加固层；额外一层

extra money───额外的钱；超速罚款单

You don't need to by extra XML security hardware just to lock down the basics of an endpoint.───你不需要额外使用XML安全硬件，只需要锁定端点的基本信息就可以。

HEADLINES screaming out the latest horrifying tales of violent crime might suggest that Americans have extra reason to lock their doors at night.───骇人听闻的暴力犯罪案件不断登上报纸头条，对美国人来说或许就更加有理由晚上紧锁自家大门了。

I'm going to buy an extra-big lock for my door, hug my kids a little tighter, and sit out the storm.───我要给我家大门买把特大号锁，把我的孩子再抱紧些，然后坐迎风暴。

Later he was surprised to find his bicycle having an extra lock with a paper: Wait and see how you can ride it.───后来他发现车子多了一道锁，并有纸条：看你如何骑。

An extra lock on the door is an added insurance against burglars.