This group of designers ________a plan for the project of the company.
Nancy enjoyed herself so much she visited her friends in Sydney last year.
______the Internet is of great help, I don’t think it’s a good idea to spend too much time on it.
It is difficult for us to learn a lesson in life______we’ve actually had that lesson.
“You can’t have this football back_____you promise not to kick it at my cat again.” the old man said firmly.
environmental damage is done, it takes many years for the ecosystem(生态系统)to recover.