When______ what his plan for his summer holiday was, he got very excited.
—_________ 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.
I gave my mother a bunch of flowers __ the evening of March 8.