It is thought that one billion people in the world,_____ is half the world’s workers, earn their living by farming.
| A．if | B．that | C．which | D．what |
Every weekend, there is a meeting and our head teacher, with five of us, ____ it.
| A．attends | B．to attend | C．attend | D．attending |
– Is everybody here?
– Not yet… Look, there ____ the rest of our visitors!
| A．comes | B．is coming | C．come | D．are coming |
Everyone, please remain ____ until the plane has come to a complete stop.
| A．seat | B．seated | C．seating | D．to seat |
I still remember ____ to the Summer Palace and what I saw there.
| A．taking | B．to take | C．to be taken | D．being taken |
The scientist’s many years’ careful observation ____ a surprising discovery.
| A．ran into | B．began with | C．led to | D．came from |