—What was the trouble with you yesterday?— When I practised running on the playground, my strength _____ and I fell onto the ground.
It's __________ comfort to know there is someone to keep __________ eye on the kids.
Now what we need is something __________ will make human beings live better.
—Would you like to play bridge with us? —Sorry. __________.
Please let me know __________ you want to go or not.
It took __________ building supplies to construct these energy-saving houses. It took brains, too.