A warm thought suddenly came to me _______ I might buy some flowers for my friend's mother’s 60th birthday.
In the USA, dog are regarded ______ friends ______ people.
He is really a friend of mine. He would _______his last penny with me.
The Smiths are going ______ separate holiday ___________.
you had better drop your parents a ________ in case (以防)they are worrying about you.
If you are left _______ on a _________land, how will tou make a living?