A new technique ____ out, the yields (收成) increased by 20% .
| A．having working | B．having been working |
| C．has worked | D．had been worked |
John’s ability to learn from observations and experience _______ greatly to his success in public life.
| A．owed | B．attached | C．related | D．contributed |
If the president had visited the hospital this morning, it ________ the headline in tomorrow's paper.
| A．will be | B．could be | C．had been | D．was |
Maybe you have been to many countries, but nowhere else _____ such a beautiful palace.
| A．can you find | B．you could find | C．you can find | D．could you find |
— Is it convenient if I call you up at 9 tomorrow morning?
— I am afraid not. I _____ a group of visiting teachers then.
| A．am meeting | B．will meet | C．will be meeting | D．will have met |
Male nurses can see things from a different angle than women and bring a male way of thinking _____problems.
| A．to solve | B．to solving | C．solved | D．of solving |