---How long do you think it will be _____China becomes a developed country?---At least 20 years, I guess.
He spoke so quickly that I didn't _____ what he said.
Every time he tried to start the car, the wheels _____ deeper into the mud.
As the storm drew near, black clouds were _____ over the sky.
The city was _____ to me, and I didn't know where to go.
The book is not _____ what we paid.