They have made medicine from a new plant _____a cure for fever.
The two military exercises were similar __________ they were both intended to give a threat to a certain country.
_________ everyone can hear the speaker, there is no _________ in turning up the radio.
Many friends sent me e-mails to _________ me on the birth of my son.
The boy the teachers considered _________ was caught __________ in the exam, which surprised us very much.
------Does Shelly like shopping?-----Well, she would rather spend time __________ at home than __________in the street.