—Who______ it be that is knocking at the door?
—It ______ be Father, but I’m not sure.
A. can; must B. can; may
. must; can D. may; must
___ is well-known to all is that the 2010 Shanghai World Expo has been brought to an end.
| A．As | B．That | C．What | D．It |
Those successful deaf dancers think that dancing is an activity sight matters more than hearing.
| A．when | B．whose | C．which | D．where |
the secret of nature, they young scientist has little time for entertainment.
| A．Devoted to betray | B．Devoting himself to bring to light |
| C．Devoted to unearthing | D．Devoting to exploring |
Her excellent performance in the competition proved that she was a winner.
| A．value | B．worthy | C．worth | D．worthwhile |
Make sure the gas is turned off after a bath, which would cause danger.
| A．somehow | B．meanwhile | C．otherwise | D．furthermore |