— Guess what! I have won the first prize in the speaking competition. — Congratulations! You _____ put a lot of work into it.

—Look at the sign! —Oh, I see.We _______ waste water.

You _______ write the poem down. Our teacher will give us a copy. 

 -- Is it your brother playing football outside? -- It ________ be him. He is helping mother with dishes now.

—Why can your neighbor know so much about London?—He ____ have been there before.