名詞 sos:

1. an internationally recognized distress signal in radio code

名詞 so:

1. the syllable naming the fifth (dominant) note of any musical scale in solmization
   同義詞：sol, soh, so

1. The bill should have been$29.54 so I round it up to$30.
   賬單本來應該是92。54美元，我湊個整數(shù)把它調高到了30美元。
2. I promise I won't spend more than a hundred pounds in the sales so don't get your knickers in a twist.
   我答應我去逛賤賣場時花費不會超出100英鎊，因此你不必驚慌。
3. The ship is sinking, and I have to send a SOS.
   船要沉了，我不得不發(fā)出緊急求救信號。