Paper-making began in China and from here it ________ to North Africa and Europe.
--- Why were you so late for work today?--- ________ to the office was very slow this morning because of the traffic.
It was impolite of him ____without ____good-bye
Development of science and technology must benefit people ______ harm them.
When you finish reading the book, you will have ______better understanding of______ life.
____ the consequences of the chemical leaks, the specialists haven’t given final conclusion before they obtain accurate statistics.