Our special thanks go to thousands of volunteers, without ________ tireless work, none of this would be possible.
Even though he has come here for almost one year, it is hard for him to fit ________ with the environment here.
________(occupy) with his work in the Satellite Launch Site, he could not spare any time to stay with his parents though they are very old.
Her talent and experience qualified her ________ the key post in the company.
In the face of all these difficulties, we're not discouraged and keep ________ good spirits.
They prepared manmade rubber as a substitute________ the natural rubber that they could no longer obtain.
