________many times, but he still couldn’t remember my phone number.
Something must be done to stop cutting down trees. ________ all the trees are cut down, the valuable soil will be washed away by the heavy rain.
Mr. Black, as far as I know, is said _______ a book on the history of the Ming Dynasty, which turns out to be a bestseller.
The contributions of some companies have ________ much improvement in the teaching and learning environment in this university.
The company has offered me a job, _________ needs great care and technique.
The plane ________ at 8:30 am, so I ________ home at 7:00 tomorrow morning.