Some insects __________ the color of their surroundings to protect themselves.
| A．take in | B．take on | C．take over | D．take off |
It never occurred to humans until the mid-1990s ______ some animals can be cloned.
| A．where | B．that | C．when | D．what |
---You look unhappy. Did you fail the tests?
--- I ______ the written papers but didn’t pass the oral examination.
| A．went through | B．went over | C．got over | D．got through |
I’ll prepare more dishes_________ your guests decide to stay for dinner．
| A．in case | B．in order that | C．even if | D．as if |
Large quantities of information, as well as some timely help _____ since the organiza
tion was built .
| A．has offered | B．had been offered | C．have been offered |
D．is offered |
---Mary’s score on the test is the highest in her class.
---Really? She ______ have studied very hard.
| A．may | B．ought to | C．must | D．should |