The little boy looked __________ at the __________ tiger.
| A．frightened; frightening | B．frightening; frightened |
| C．frightened; frightened | D．frightening; frightening |
It was not until he came back _____ he knew the police were looking for him.
| A．which | B．since |
| C．that | D．before |
Was _____ that I saw last night at the concert？
| A．it you | B．not you |
| C．you | D．that you |
It is _____ my father worked _____ I work now.
| A．where, that | B．where, when |
| C．that, where | D．that, that |
It is the protection for the trees _______ really matters, rather than how many trees are planted.
| A．what | B．that |
| C．不填 | D．which |
It is _______ he often fails in exams ______ makes his parents worried about him.
| A．what； that | B．that； what |
| C．that； that | D．/ ； that |