Everyone knows fire is very useful in our daily life, it is also dangerous.
Mrs. Brown was much disappointed to see the washing machine she had had____ went wrong again.
___ smoking here will be fined.
---- “Alice, why didn't you come yesterday?”----- “I______, but I had an unexpected visitor.”
I met several people there, two of _____ being foreigners.
----“Where is it?”----- “Where is _____? I don't know what do you mean?”