Since Tom ______ downloaded a virus into his computer, he can not open the file now.
| A．readily | B．horribly | C．accidentally | D．irregularly |
This problem may lead to more serious ones if ____ unsolved.
| A．making | B．remained | C．keeping | D．left |
She felt sorry that she had disturbed the ____ calmness of a man she respected.
| A．regular | B．curious | C．usual | D．various |
If you live in the country or have ever visited there, ____ are that you have heard birds singing to welcome the new day.
| A．situations | B．facts | C．dances | D．possibilities |
His letter was especially welcome as I ____ from him for long.
| A．haven’t heard | B．would not heard | C．hadn’t heard | D．didn’t heard |
——Would you mind giving your advice on how to improve our business management?
——if you make ____ most of the equipment, there will be ____ rise in production.
| A．不填；不填 | B．the；a | C．不填；a | D．the；不填 |