Radium salts, which have been found to _____ in bones, give rise to cancers of the bone.
The man in black was about to set fire to the house ____ the police came.
. I walked out of the cinema, _____ I’d never come back to this hell.
Three hundred firemen raced to the hotel after a smoke detector(检测器)_____ the alarm soon after midnight.
Can you _____ the point? If you can, please explain it to me.
With the boy _____ the way, we had no trouble _____ the way to lead to Zhongshan Park.