____the plan has been made, let’s get down to ____it out.

Most of the roads were covered with thick snow, ____ made our journey more difficult．

Look at the new computers, of ______ none are produced abroad.

The problem of the present world is that those who are imaginative have little experience_________those who are experienced have weak imagination.

-Do you know the boy________ is sitting next to Peter?-Yes. He is Peter's friend. They are celebrating his ________ birthday.