_________ that causes heavy haze sweeping over china remains unknown to many scientists.
| A．what it is | B．what is it |
| C．who is it | D．who it is |
It’s______ great pleasure for him to be invited to the party.
| A．/ | B．a | C．an | D．the |
—Have you seen ______Audi car I parked here?
—Is it ______red one?A young lady has driven a red car away.
| A．an;a | B．the;the |
| C．the;a | D．an;the |
______page of the book is torn andcover looks very old.
| A．The；the | B．A；a |
| C．A；the | D．The；a |
Tom’s and John’s______came to London last week.
| A．father-in-law |
| B．fathers-in-law |
| C．fathers-in-laws |
| D．father-in-laws |
The city government decided to keep the old temple for its historical_____.
| A．price | B．cost | C．value | D．usefulness |