They could have attended the awarding ceremony，but their flight due to the bad weather．
| A．was delayed | B．had been delayed |
| C．has delayed | D．was delaying |
Why are you leaving right now? You promised to stay ____ hours.
| A．both two | B．more two |
| C．two another | D．another two |
We asked John and Jerry, but ____ of them could offer a satisfactory explanation.
| A．either | B．none | C．both | D．neither |
This book______18 articles , _______ three written by my father.
| A．contains; includes | B．includes; contains |
| C．contains; including | D．includes; containing |
Chest pains can be a warning ____of heart problems.
| A．signal | B．sign | C．mark | D．symbol |
_______ is mentioned above, the number of the students in senior high school is increasing.
| A．It | B．That | C．What | D．As |