(2012·安徽) A lot of language learning, __________ has been discovered, is happening in the first year of life, so parents should talk much to their children during that period.
They _________to see you off at the airport, but they got there too late.
-- Excuse me, Sir. You_________take your camera into the museum. -- Sorry, I didn't know and I promise you I_________.
Jane didn't say_________she would return, but I suppose she'll be back for dinner.
What an accident! If the driver_________ carefully, things would not be as they are.
The price_________recently. I wonder whether it will remain so.