---Be careful. You might fall into the river.---Thank you. I ________ I ________ so close to it.
He doesn’t do his homework___________, though he has ___________.
—_________ was light bulb invented ________ ? —Thomas Edison.
Some students enjoy raising pet dogs while__ don't agree with them.
The twins have tried, but__ of them has got the chance to study abroad.
I think the skirt on the desk can't be Lucy's. _is made of- wool.