If you ___ stick to the unrealistic approach, the worse result will be waiting for you not far ahead.

Our playground is not so tidy and beautiful as before, students must ____ dirty things on it.  

It was a fine day yesterday. I ________ have taken my raincoat with me.

With the help of the new technology, you __ e-mail your friends by mobile phone.

– Amazing! You _____ have won the first prize in the national English speech contest!– I’m lucky that all my efforts have finally paid off.