______ at the door before you enter my room, please.
| A．Knock | B．Knocking | C．Knocked | D．To knock |
It was because he was ill ______ we decided to return home.
| A．why | B．that | C．when | D．where |
Laws are what keep society ______ and the nation at peace.
| A．in order | B．in need | C．in fact | D．in existence |
_______ greatly by what he had heard and seen, he made up his mind to stand on his own feet again.
| A．Inspiring | B．To be inspired | C．Being inspired | D．Inspired |
It is a surprise for me to see that these old-fashioned machines are still ________ in the big city.
| A．in order | B．in use | C．in danger | D．in difficulty |
The medical team, three doctors and two nurses, _______ for the mountain area yesterday.
| A．put off | B．put up | C．set about | D．set off |