Every few years, the coal workers their lungs X-rayed to ensure their health.
Do you know when Mr. Brown _______? When he _______ , please let me know.
My uncle _____ to see me. He'll be here soon.
Look out! That tree _____ fall down.
Everyone likes to live in a house ______ windows face the south.
They talked about the persons and things ______ they remembered at school.