It sounds like a good idea, but it _________ to be seen whether it will succeed.
Last term our maths teacher set so difficult an examination problem _____ none of us worked out.
_____ all the inventions have in common is ______ they have succeeded.
-What shall we have for dinner tonight? -Oh,I don’t care. ____. It’s your job to come up with the menu,so get on with it.
Mr. Green left _________ suddenly _________ he came.
Why are you always making the same mistake? Think of _____ I told you.