The research project has only been ______ for three months, so it’s too early to comment on its success.
Charles Babbage is generally considered ______ the first computer.
"Can’t you read?" Mary said ______ to the notice.
Look, they seem _____ about you.
My brother ______singing ______ dancing while I _____ dance _____sing.
Mr. Chen is a teacher and works very hard. _________ his wife.